Article

The horticultural industry as a vector of alien snails and slugs: Widespread invasions in Hawaii

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

The horticultural industry is an important vector of alien snails and slugs. Surveys of nurseries in the Hawaiian Islands recorded 31 terrestrial snail/slug species, all but two of them alien and five previously unrecorded. Individual facilities had 1–17 species. In total, 38 non-native terrestrial snail/slug species have become established, originating globally. Numbers on each island do not reflect numbers of survey locations but rather the total numbers established on each island. Species richness and community composition in nurseries differed significantly among islands and among different-sized nurseries. Certain species were more common on Oahu (main port of entry to Hawaii) so most of these alien species may have been first introduced to Oahu and then spread to other islands. Some of them cause damage in nurseries. Some may cause shipments of nursery products to be rejected when they are inadvertently exported with them. When they are transported to and become established in new areas they may cause agricultural, horticultural and environmental problems. Greater awareness of these species is necessary in the nursery industry and among quarantine officials.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... In contrast, land snails are easily, though often unintentionally, transported through human activities; for example, land snails enter the United States on commodities such as flowers, plants, and tiles [20], among other modalities [21]. Within the United States, evidence indicates that the plant trade is a primary means of snail transport [22,23]. Common in plant nurseries [22][23][24], snails can be introduced into yards [25], green roofs [26], and other planted areas. ...
... Within the United States, evidence indicates that the plant trade is a primary means of snail transport [22,23]. Common in plant nurseries [22][23][24], snails can be introduced into yards [25], green roofs [26], and other planted areas. As a consequence, urban areas contain a combination of native, human-associated, and non-native snails [27][28][29][30]. ...
... It is likely that slugs occur elsewhere in the OKC Zoo and may be visible after rains. One or both of the slug species are commonly found in plant nurseries [23,24,36]. Deroceras laeve occurred in 19 of 28 surveyed plant nurseries in Oklahoma, and A. valentianus was found in 14 of these nurseries [22]. ...
Article
Full-text available
The combination of animals and plants in zoological gardens provides the opportunity for conservation within the grounds. An example is pollination gardens that support free-moving butterflies and bees. Pollination gardens and other areas with plants also support a wide range of other non-captive animals, including soil-associated invertebrates. This study targeted land snails, a species-rich group that links the brown decomposition food web and the plant-based web that is preyed upon by fireflies and birds, among others. A survey of 24 sites within the Oklahoma City Zoo and Botanical Garden revealed a diverse snail fauna of 23 species. The majority were native species but included 10 non-native species that are common regional urban species, likely introduced through the plant trade. No distributional pattern of snails was evident, probably because of the similar management scheme throughout the zoo. Snails and other observed soil-associated invertebrates (e.g., isopods, millipedes, and earthworms) support non-captive birds and other animals. Lightly managed areas with leaf litter and downed wood are especially conducive to snails and other soil-associated invertebrates and are nesting sites for bees. These communities can form conservation demonstration areas that can be the basis of educational programs, including outreach programs.
... Reports of snail interceptions and requests for identifications were brought to the attention of the Malacology staff at BPBM and prompted surveys for newly introduced species. All surveys for snails were carried out by at least two experienced snail researchers following visual search protocols described in Cowie et al. (2008) for nurseries and by Durkan et al. (2013) in residential and surrounding areas. Snail identifications were done via an integrative approach using conchology, reproductive anatomy, and DNA barcode analyses. ...
... All the sequences from US populations show close affinities for those from the Iberian Peninsula. Zachrysia provisoria appears to be most likely introduced from populations in Florida along with nursery trade materials, which is a well-known pathway for introduced species into Hawaii (Cowie et al. 2008). ...
... By comparison, the more than 750 endemic species of land snails in Hawaii are thought to be the result of fewer than 23 colonization events over more than five million years, which is fewer than one successful dispersal event every 200,000 years (Zimmerman 1948;Ziegler 2002). Since 2008, 40 newly established non-marine, non-native snail species have been recorded in Hawaii (Kraus 2003;Hayes et al. 2007;Cowie et al. 2008;Hayes et al. 2012;Hayes et al. unpublished data). While some of these new records are the results of revised identifications to previously established taxa, others represent newly established species that probably existed in sleeper populations long before being detected. ...
... List based on species recorded in horticultural facilities on the Hawaiian Islands according to Cowie et al. (2008), Hawaiian native species excluded, and Discostrobilops hubbardi from this study; nomenclature updated according to MolluscaBase (2020). Comparative data = number of species of the genus with sequence for COI in GenBank/number of accepted species in genus according to MolluscaBase (2020). ...
... In order to check the general feasibility of molecular identification we analysed the availability of genetic data for a greater set of snail species relevant in horticultural trade, thus for the focus of our study. We based our selection on the fairly comprehensive and representative list of species recorded in horticultural facilities on the Hawaiian Islands (Cowie et al., 2008) and excluded the Hawaiian native species. GenBank was searched for available sequence data for COI and 16S for all respective species by the taxonomy search tool in nucleotides. ...
... but possibly including some Tornatellaria spp.") in their survey of horticultural facilities on the Hawaiian Islands which could hint at multiple sources of Tornatellides species in greenhouses. Considering the recent find and the observations by Leonhardt & Sewake (1999), it should be investigated if those occurrences stem from native Hawaiian species as assumed by Cowie et al. (2008). Also Ovachlamys fulgens was found in nine of 40 surveyed horticultural facilities on four of the Hawaiian islands, which also suggests the spread with the trade of plants. ...
Article
Full-text available
Three previously unreported species of tropical land snails were found in the greenhouses of the Gothenburg (Göteborg) Botanical Garden and the Public Science Center Universeum in Gothenburg. For Tornatellides cf. boeningi (Schmacker & Boettger, 1891) and Ovachlamys fulgens ( Gude, 1900 ) this is the first observed occurrence in a European greenhouse, while Discostrobilops hubbardi ( Brown, 1861 ) was first reported very recently in the Vienna Botanical garden. Tornatellides and Discostrobilops seem to be spread with orchid culture and trade. Identification of the Tornatellides species proved extremely difficult and a genetic sequence-based approach completely failed due to the unavailability of reference data. This was unexpected considering the importance of these introduced species in horticultural trade. A broader assessment of available sequence data for genetic identification based on COI or 16S for other snail species reported from horticultural facilities showed that such reference data in GenBank are still scarce and only for a limited number of species this approach would support identification.
... Slug is the common name used for any gastropod mollusc with apparently no shell or a much-reduced shell, or only a small internal shell. Though slugs are generally not plant pests, those that feed on higher plants tend to be defoliators, causing damage similar to caterpillars and other insects (Cowie et al. 2008;South 2012). Some terrestrial slugs and snails have been inadvertently spread by man well beyond their natural range (Hanna 1966;Barker 1979;Robinson 1999;Cowie 2001;Herbert 2010). ...
... Alien species are being moved around the world at an unprecedented rate as a result of the globalization of trade and the greatly increased ability of people to travel widely as evident from the increase in the number of reports of alien species recently (Cowie et al. 2008;Hirano et al. 2019;Alonso et al. 2019;Serniotti et al. 2019). A rapid increase in the number of species introduction (accidental or intentional) is resulting in the displacement of native species and is becoming a serious threat to the regional biodiversity, worldwide (Lowry et al. 2013). ...
... Consistent reports, from various parts of the world over the past two to three decades, suggest that the horticultural industry, in addition to its role as a vector of invasive plants (Dehnen-Schmutz et al. 2007), is perhaps the most important vector of these small snails and slugs, at least as measured by the numbers of interceptions by quarantine officials (Cowie and Robinson 2003). In a case study on the Hawaiian Islands 31 terrestrial snail/slug species were recorded, all but two of them alien and the horticulture industry is depicted as the source (Cowie et al. 2008). It is important to mention that the Indian horticulture Industry had a steady increase after the National Horticulture Mission of the Govt. of India during 2005-06 (Ramesh et al. 2017). ...
Preprint
Full-text available
The members of the heterobranch family Veronicellidae Gray, 1840 (commonly referred to as leatherleaf slugs) include some of the most widespread and agriculturally damaging invasive slugs. In a recent survey at Sagar Island of Sunderban Biosphere Reserve, four specimens hitherto unknown from the Reserve were collected. The specimens were identified as Laevicaulis haroldi Dundee, 1980, a native of South Africa. The first observation of this species in India was noted during 2005 in Maharashtra and recently from Uttar Pradesh. The current record from West Bengal affirmed this slug to be an invasive alien species in India. Categorized as IUCN-Endangered in its native range, this species might have a wider distribution in India. In addition, the current study underscores the need of identifying invasive alien species and quantifying their population dynamics in India.
... Many gastropods have spread and naturalized in areas outside their native range due to human activities (Cowie and Robinson, 2003). The most important inadvertent pathway responsible for the introduction of small animals such as snails and slugs is perhaps horticultural trade (Robinson, 1999;Cowie and Robinson, 2003;Hayes et al., 2007;Cowie et al., 2008;Pergl et al., 2017;Darrigran et al., 2020;Shivambu et al., 2020). If there are no controls in place, these species may become pests in their new environments, causing damage to crops and decreasing production. ...
... Studies concerning horticultural trade mainly refer to a single species of mollusks and few studies have been conducted in mollusks in plant nurseries (e.g. USA: Cowie et al., 2008;Bergey et al., 2014;Europe: Meeuse and Hubert, 1949;Horsák et al., 2004). Furthermore, studies in South America are lacking. ...
... Despite the rules and regulations in plant nursery management, these garden centers continue to be a potential cause of dispersal of slugs and snails. Good nursery hygiene, use of the appropriate pesticide/ molluscicide, and mechanical barriers may adequately reduce their spread and possible damage (Cowie et al., 2008). In this study, only two of 12 nurseries used molluscicides in pellet form (metaldehyde) for pest management. ...
Article
Full-text available
Llimacs terrestres en vivers, una possible causa de dispersió a l’Argentina Els vivers comercials poden causar la dispersió de cargols i llimacs terrestres (natius i no natius) a través del comerç de plantes i el consegüent transport d’ous i petits individus que poden passar desapercebuts. No hi ha estudis sobre el possible paper dels vivers com a causa potencial de dispersió de llimacs a l’Amèrica del Sud. En revisions sobre introducció accidental d’espècies no natives a l’Argentina durant els últims anys, es va constatar que diverses introduccions es van produir a través del comerç de plantes. Per explorar el paper dels vivers comercials vam recol•lectar i identificar llimacs en 12 vivers comercials de dues ciutats de la província de Buenos Aires (Argentina) i vam registrar vuit espècies de llimacs. Vam validar Deroceras laeve i Belocaulus angustipes per a l’Argentina i vam confirmar la presència d’Ambigolimax valentianus, que va ser citat recentment a l’Argentina. Recomanem que els vivers siguin monitorats regularment atès que las espècies de cargols i llimacs es registren accidentalment juntament amb la terra i les plantes comercialitzades. Dades publicades en Zenodo (Doi: http://doi.org/10.5281/zenodo.4304621)
... The species was first described from Réunion Island (as Île Bourbon), Mascarene archipelago, in the western Indian Ocean (Potiez and Michaud 1838), but Griffiths and Florens (2006) thought it an East African species introduced into the Mascarene islands. The hypothesis that the species is native to Africa or East Africa was also maintained by Kerney and Cameron (1979), Robinson (1999), Probst (2001), Shea (2007), Cowie et al. (2008), Stanisic et al. (2010), and Foon et al. (2017). However Rowson et al. (2010) observed that Verdcourt, familiar with A. clavulinum in botanic gardens of the UK, never reported it from East Africa (e.g., Verdcourt 1983Verdcourt , 2000Verdcourt , 2006. ...
... Opeas hannense is regarded as native to tropical America (Pilsbry 1946;Kerney and Cameron 1979;Deisler and Abbott 1984;Cowie 1997;Cowie et al. 2008;Brook et al. 2010;Miquel and Herrera 2014) where it is widespread in Central America and the West Indies. On the contrary Robinson (1999: Table 1) regarded it as native to East Asia. ...
Article
Full-text available
Plant trade and exchange for horticulture, recreation or research play a significant role in the dispersal of molluscs. Alien slugs and snails accidentally introduced into Europe have established rich communities in several countries, but although these introductions could have ecological and economic implications, mollusc xenodiversity in Italian botanical gardens, plant nurseries, and greenhouses has never been investigated. Facilities throughout the country were therefore visited between 2017 and 2023. Here the list of the achatinoidean species so far recorded from Italian greenhouses is provided, giving a short description of their diagnostic characters. The greenhouses of Trento and Padua host interesting assemblages of achatinoideans: the results of this study include the first reports of four achatinids, namely Allopeas clavulinum, Opeas hannense, Paropeas achatinaceum and Subulina octona from Italy and the first record of Geostilbia aperta from Europe. Reproductive anatomy of all species except Geostilbia aperta is illustrated in detail, integrating anatomical knowledge of this group of tiny molluscs, some of which are known mainly from their shell characters. The systematics of all the species is discussed, highlighting topics for future research (e.g., status of Allopeas mauritianum, real identity of Helix hannense, anatomy of Opeas hannense, species-level taxonomy of Subulina, systematic relationships and species-level taxonomy of Geostilbia).
... An estimated 70% are already extinct and many of the remaining taxa are in decline (Solem et al. 1990;Lydeard et al. 2004;Régnier et al. 2015b;Yeung and Hayes 2018). Hawaii also has more than 40 established non-native snail species (Cowie et al. 2008;Hayes et al. 2012). The 27 species (17 Hawaiian native and ten non-native) sampled in this study represent both rare and abundant taxa across phylogenetically diverse snail families and a range of sizes and habitat types (freshwater, terrestrial, and marine). ...
... Lines indicate best-fit models for the relationship between shell dimension size and total success. Shell dimensions are (A) Height (mm), (B) Width (mm) deaths post FTA sampling in this study, Bradybaena similaris and Planorbella duryi, which are widespread invasives (Cowie et al. 2008). Régnier et al. (2011) indicated that a major advantage of FTA cards is that they do not impact the chances of an individual's survival in the field, and therefore are a convenient option for non-lethal field sampling, but this study demonstrated otherwise for two endemic Hawaiian species. ...
Article
Full-text available
Sampling the DNA of rare animal species should have minimal impacts on individual health. This can be accomplished through non-lethal/non-invasive sampling. Few of these methods have been developed for invertebrates, including the Mollusca, which are in global decline. Tissue clipping the foot is a common non-lethal method for gastropods. However, it causes permanent damage and is inappropriate for smaller snails. This study used Flinders Technology Associates (FTA) cards to sample DNA from snail mucus for species of different sizes and habitat types, and across evolutionarily distant lineages. In a survival assay, the death rate of individuals sampled with FTA cards (12.1%) was greater than in the controls (3.7%), but the difference was not significant. Of 224 individuals representing 27 snail species (17 Hawaiian native, ten non-native) sampled using both FTA cards and tissue clipping, 80.4% of FTA samples and 91.6% of tissue samples amplified for COI, a significant difference. COI sequencing success did not differ significantly between the two methods. For individuals that failed to produce a COI sequence, an attempt was made to sequence 16S. For 16S, amplification and sequencing rates did not differ significantly between FTA and tissue samples. Habitat type and shell size did not affect FTA sampling success. Phylogenetically basal taxa exhibited lower success rates, but this may have been because of difficulty in sampling operculate taxa, and not because of identity. These results indicate that the FTA sampling is a viable non-lethal alternative to tissue clipping and can be used for diverse gastropods.
... Approximately 100 species of land snails have proven to be highly adaptive to environmental changes brought about by human activities, and often become a highly abundant and characteristic component of invertebrate fauna in modified habitats (Barker 2001). Most species have been introduced outside of their native range by passive dispersal associated with human trading activities, and some are invasive when introduced into new areas (Barker 2001;Cowie et al. 2008;Kim et al. 2016;Hirano et al. 2019bHirano et al. , 2022. The East Asian region, particularly Japan, is a hotspot for endemic terrestrial mollusks (Azuma 1982;Minato 1988). ...
... These results revealed that both natural processes and human activity may have affected the expanding distribution of both bradybaenid snails. For instance, nursery trade could be a factor in the introduction of terrestrial mollusks outside of the native range (Cowie et al. 2008). Also, the average temperature of Japan has risen at a rate of 1.24 °C in the past 100 years (Japan Meteorological Agency 2020), which might have assisted in the recent expansion of the distribution of B. pellucida. ...
Article
Full-text available
Understanding the method and history of introduction in non-native species are essential for conservation biology, especially in regions like Japan that have a long history of human activity. Bradybaena similaris is a circumtropical land snail that is considered a non-native species from Southeast Asia or East Asia to Japan, which was believed to be introduced by human activities such as sugarcane or sweet potato establishment several hundred years ago. Bradybaena pellucida, a sister species of B. similaris, is native to western Japan, but has recently spread throughout the eastern part of the country. We investigated genetic diversification pattern of non-native organisms using the two land snail species. We clarified the phylogenetic relationships of B. similaris and B. pellucida based on genome-wide SNPs and mtDNA. We revealed the population demographic history using ABC analysis with SNP data. Bradybaena similaris of mainland Japan could be distinguished from populations on the continent. Introgressive hybridization between the species occurred approximately 29,700 years ago. The present findings provide two new hypotheses: that agriculture began in Japan about 2800 years ago, Japanese populations of B. similaris were introduced from the continent more than 29,000 years ago by human activity other than agriculture; or B. similaris is native to a part of mainland Japan. The history of a non-native species with human activity is complex, urging us to reconsider previous hypotheses.
... An estimated 70% are already extinct and many of the remaining taxa are in decline (Solem et al. 1990;Lydeard et al. 2004;Régnier et al. 2015b;. Hawaii also has more than 40 established non-native snail species (Cowie et al. 2008;Hayes et al. 2012). The 27 species (17 Hawaiian native and ten non-native) sampled in this study represent both rare and abundant taxa across phylogenetically diverse snail families and a range of sizes and habitat types (freshwater, terrestrial, and marine). ...
... The signi cantly higher number of deaths of the Auriculella uniplicata and Auriculella turritella sampled with FTA, some of which were sampled in the eld and transported back to the lab for further observation, ( (Solem 1990). It can be reasonably assumed that it is more sensitive to environmental stressors than the generalists that experienced no deaths post FTA sampling in this study, Bradybaena similaris and Planorbella duryi, which are widespread invasives (Cowie et al. 2008). Régnier et al. (2011) indicated that a major advantage of FTA cards is that they do not impact the chances of an individual's survival in the eld, and therefore are a convenient option for non-lethal eld sampling, but this study demonstrated otherwise for two endemic Hawaiian species. ...
Preprint
Full-text available
Sampling the DNA of rare animal species should have minimal impacts on individual health. This can be accomplished through non-lethal/non-invasive sampling. Few of these methods have been developed for invertebrates, including the Mollusca, which are in global decline. Tissue clipping the foot is a common non-lethal method for gastropods. However, it causes permanent damage and is inappropriate for smaller snails. This study used Flinders Technology Associates (FTA) cards to sample DNA from snail mucus for species of different sizes and habitat types, and across evolutionarily distant lineages. In a survival assay, the death rate of individuals sampled with FTA cards (12.1%) was greater than in the controls (3.7%), but the difference was not significant. Of 224 individuals representing 27 snail species (17 Hawaiian native, ten non-native) sampled using both FTA cards and tissue clipping, 80.4% of FTA samples and 91.6% of tissue samples amplified for COI, a significant difference. COI sequencing success did not differ significantly between the two methods. For individuals that failed to produce a COI sequence, an attempt was made to sequence 16S. For 16S, amplification and sequencing rates did not differ significantly between FTA and tissue samples. Habitat type and shell size did not affect FTA sampling success. Phylogenetically basal taxa exhibited lower success rates, but this may have been because of difficulty in sampling operculate taxa, and not because of identity. These results indicate that the FTA sampling is a viable non-lethal alternative to tissue clipping and can be used for diverse gastropods.
... Information on dispersal, habitat requirements, and resource use by both species is limited, and their morphological near-identity requires either molecular or anatomical dissections for unambiguous species identification. It is likely that both slug species were accidental introductions via horticulture (Cowie et al. 2008). ...
... slugs and S. grossa spiders in valve boxes. Human-mediated dispersal of these taxa presumably facilitates rapid colonization of emerging suitable habitat throughout this urban region, as has been shown for land snails (Bergey 2019), and could easily occur by the movement of slug egg-containing soil from nurseries (Cowie et al. 2008). Landscape connectivity for these species may therefore be high in their urban, introduced range, potentially comparable to, or even higher than, within their native range. ...
Article
Full-text available
In Southern California, irrigation infrastructure is a prerequisite for urban green space management, and valve boxes are installed widely to manage water flow. These below-ground, plastic boxes protect valves and manifolds, create space for connecting pipes, and present a scarce ecological resource—elevated humidity and shelter from potential predators. We provide the first systematic survey of the biodiversity of valve boxes and evaluate their role in the establishment of non-native species. We conducted comprehensive surveys of slug and spider refugial habitat elements, including leaf litter, crevices, decaying logs and other cover objects, and valve boxes, across urban Greater Los Angeles and adjacent wildland areas. We found that valve boxes comprised nearly all of the surveyed habitat for three common non-native species, including two slugs in the genus Ambigolimax and a spider in the genus Steatoda. At 83 of 85 sites, we detected these species only in valve boxes and not in any other habitat elements. While valve boxes were significantly more frequent in urban than wildland areas, detections in wildland areas were also largely restricted to valve boxes. All of these species share a preference for elevated levels of humidity, and we speculate that introduced slug and spider taxa within irrigation infrastructure may be a general feature of many urban areas, especially in relatively xeric climates with locally high densities of valve boxes. Under these conditions, irrigation infrastructure likely facilitates the establishment and persistence of non-native species requiring high humidity throughout the urbanized world, and could contribute to their cosmopolitan distribution.
... Forcart (1967) and Raheem et al. (2014) attributed its possible occurrence in India and elsewhere through the introduction of flowering plants from different countries as also inferred by others. The slug has been studied in detail on various aspects (morphology, morphometry, anomaly, colour variation, systematics, Karyology, distribution, population dynamics, food & feeding, breeding, incidence on palm seedlings, control measures, nematode hosts, influence of temperature, diseases, intermediate host etc.) by a number of workers during the past (Rao & Ramdoss, 1953;Ray,1961;Brar & Simwat, 1973;Kulkerni & Nagabhusam, 1973;Rao & Mitra, 1979;Godan, 1983;Rao et al., 1989;Muthumani et al., 1992;Rao et al., 1995;Panigarhi, 1997Panigarhi, , 1998aPanigarhi, -c, 1999aPanigarhi, -c, 2000aKulkerni et al., 1998;Kumar et al., 1998;Raut & Mandal, 1984, 1986Rao & Mitra, 1991;Mitra & Dey, 1992;Kumar et al., 1998;Raut & Panigrahi, 1988a,b, 1989, 1998, 1990, 1991aRao et al., 1997;Raut, 1999;Kumar & Ahmed, 2000;Mookherjee et al., 2000;Murugan & Chandran, 2001;Dey et al., 2003;Herbert & Kilbum, 2004;Rao et al., 2004;Mitra et al., 2005;Kumari & Thakur, 2005;Patil & Tamale, 2005;Kalidas et al., 2006;Cowie et al., 2008;Cordova et al., 2010;Ramakrishna et al., 2010;Patil & Talmale, 2011, 2012Brodie & Barker, 2012;South, 2012;Jayashankar et al., 2014;Raheem et al., 2014;Budha et al., 2015;Das & Parida, 2015;Selvi et al., 2015;Kim et al., 2018;Das, 2020;Sajan et al., 2021;wikipedia.org). The species has been recorded from various states of India but no record is available from Jharkhand and Uttarakhand. ...
... However, larger individuals may be found active during the day (Rao et al., 1989;Raut & Panigrahi, 1990;Panigrahi, 1999a). They defoliate the host plants like caterpillars and other insects (Cowie et al., 2008;South, 2012). Breeding: Protandric hermaphrodite (changing sex from male to a female). ...
Article
Full-text available
Laevicaulis alte, the Tropical Leather-leaf Slug is an invasive African slug, that got introduced into India. Recently specimen was sighted at Dehra Dun (Uttarakhand) and Jamshedpur (Jharkhand), India which are new records from these areas. In the present communication, its systematic account, distribution, control measures, and other aspects have been dealt with.
... However, Vaginula behni Semper, 1885, that is currently a synonym for S. plebeia according to Thomé (1993), was originally described based on material from Rio de Janeiro, Brazil, what indicates that it is present for a long time in South America as well. Besides, the other species of the genus is also found in America and Sarasinula has relationships with other American genera (Dayrat et al., 2011), supporting the American origin hypothesis for S. plebeia, as postulated by Cowie et al. (2008). Currently, S. plebeia is registered in South America in the following countries: Brazil (since 1885), Colombia (1978), Venezuela (1992), Chile (1993, without specifying location), Ecuador (2008) and Peru (2015) (Thomé, 1993;Darrigran et al., 2020). ...
... However, the occurrence in two different ecoregions indicates that their presence in Argentina is possibly due to different events. Since S. plebeia is considered to have a neotropical origin as mentioned by Cowie et al. (2008), the presence in Argentina, surely due to human activity, is within its potential distribution. For this reason, the presence in Argentina can be considered as a "Transplant of species" as defined by Pérez et al. (2007). ...
Article
Full-text available
Sarasinula plebeia is a common land slug in tropical and subtropical areas, including South America. This species is known as Bean-slug but considered a pest of great importance in numerous crops, horticultural facilities, plant nurseries, and garden. Also, it is a natural host for nematodes that cause parasitosis in different countries. We report for the first time the occurrence of Sarasinula plebeia in Argentina, based on material collected in the provinces of Chaco and Misiones, extending the distribution of the species in South America to 34 terrestrial ecoregions.
... Mexico to Brazil, southward to São Paulo state (Simone 2006); including the city of Rio de Janeiro (eg Alexandre et al. 2017;Rangel et al. 2021). It has been introduced in Hawaii and Europe (Cowie et al. 2008;. ...
... Similarly, reports from various countries suggest that the horticultural industry is perhaps the most important vector for introductions of small snails and slugs. For example, 31 such terrestrial species, all but two of them alien and five previously unrecorded, were found in the nurseries of native Hawaiian plants destined for local restoration projects (Cowie et al. 2008 ). However, although the impact costs are relatively well established for agriculture, industry (e.g., water companies or forestry), and property, the financial costs in terms of biodiversity impacts from nonnative invasive species remain comparatively poorly understood and hard to calculate and are therefore often excluded (Hanley andRoberts 2019 , Cuthbert et al. 2021 ). ...
Article
Full-text available
The multibillion dollar ornamental plant trade benefits economies worldwide, but shifting and rapidly expanding globalized supply chains have exacerbated complex environmental, sustainability, and biosecurity risks. We review the environmental and social risks of this international trade, complementing it with analyses of illegal trade seizures and plant contaminant interception data from the Netherlands and the United Kingdom. We show global increases in ornamental plant trade, with supply expansions in East Africa and South America, and highlight risks and impacts including biodiversity loss, aquifer depletion, pollution, undermined access and benefit sharing, and food security. Despite risk mitigation efforts, the interception data showed considerable volumes of contaminants in ornamental plant shipments, but taxonomic identification was not always possible, highlighting uncertainties in assessing biosecurity risks. With high-volume and fast-moving transit of ornamental plants around the world, it is essential that production standards are improved and that data on specific risks from trade are collected and shared to allow for mitigation.
... Additionally, the penis in the reproductive system is short and smooth without annular protrusion, with enlarged glands. The digitiform gland with an elongated form with seven tubules varying in length (Fig. 1E), and this finding was confirmed by Cowie et al. (2008) who found that the number of digitiform tubules in S. plebeia reproductive system is exactly seven. This represents a main distinct between S. plebeia and the other veronicellid species like Laevicaulis stuhlmanni which was recorded recently in Egypt by Ali (2017); Metwaly and Ali (2024) indicated that the number of digitiform tubules in this slug is around fourteen tubules. ...
... However, the non-native weevil has caused the decline of rare native thistle species in North America such as Cirsium canescens (Platte thistle) and Cirsium pitcheri (Pitcher's thistle) (Louda et al. 1997. Several slug and snail species have been introduced to the Hawaiian Islands through the horticulture industry (e.g., Achatina fulica, Deroceras laeve, Bradybaena similaris, Veronicella cubensis) (Cowie 2000(Cowie , 2001Cowie et al. 2008). Joe and Daehler (2008) found that non-native slug species (D. laeve, Limacus flavus, Limax maximus, Meghimatium striatum) contribute to the decline in populations of the endangered native plant species Cyanea superba and Schidea obovata due to herbivory. ...
Article
Full-text available
Prior to the arrival of Europeans in North America, forest and grasslands individually covered a 3rd of the conterminous United States; however, following the colonial and pioneer periods, respectively, these land cover categories were reduced to 70% and 50% of their original prominence. The dominant driving force for native land conversion was agriculture, which expanded exponentially from the Atlantic to the Pacific, comprising over half the total land area of America at its peak in 1950. However, farmland area has subsequently declined by 25%, so what has been driving native plant declines north of the 30th latitudinal parallel over the past 75 years? Analysis of recovery plans issued by the U.S. Fish and Wildlife Service indicates that of the over 900 plant species “listed” as threatened and endangered the primary driver of decline was invasive species, followed by habitat alteration, and development, which collectively accounted for 93.2% of the primary drivers for listed species. In Canada, these three drivers of decline were the primary drivers for 81% of listed species. Comparatively, herbicides were identified as the primary or secondary driver in 13 out of 1124 cases (1.2%). Given that agricultural land area is contracting in the U.S. and Canada, there appears to be a misconception that agrochemicals are the seminal cause of native plant decline. Here, we explore the individual contribution of drivers relative to the historical events of North America to provide context and perspective as well as focus and prioritize conservation efforts accordingly.
... Border inspections capture a wide range of species being carried on plant material (cultivated plants, flowers and foodstuffs), on Mediterranean-origin tiles, and in association with other goods (Robinson, 1999 ). Within countries, the plant trade is commonly cited as a route of snail dispersal (Cowie et al. , 2008 ;Bergey et al. , 2014 ;Yeung et al. , 2019 ;Gutiérrez Gregoric et al. , 2020 ), especially as plant nurseries can provide breeding grounds and transfer points for a number of 'travelling' species. For many snail species and locations, the precise method of introduction is unknown, but some type of transportation, often associated with commerce, is implicated (Cowie, 1998 ;Cowie & Robinson, 2003 ;Peltanová et al. , 2012 ). ...
Article
Full-text available
Biotic homogenization or the increasing similarity of biota has been documented in urban land snail assemblages in Europe and North America. The resulting biotic homogeneity is caused by a loss of native species and the establishment of non-native species. Climate affects land snail distributions, and because Thailand (exclusive of the southern peninsula) has an almost uniform climate, we hypothesized that urban land snail populations would show a high degree of taxonomic homogeneity. We sampled 76 sites (e.g. yards, temple grounds, restaurants and hotels) over a 38-day period during the rainy season in 2022. These sites included three regions: central (five provinces), north (two provinces) and northeast (five provinces). Both live snails and shells were counted, and the 10,470 counted individuals represented 25 taxa. Biotic homogeneity was indicated by three taxa comprising 69.9% of individuals. By far the most abundant species was the native species Sarika siamensis, which was found at all 76 sites and comprised 50.4% of all individuals. The other two abundant species were non-native species—the giant African snail Lissachatina fulica (60 sites) and Allopeas gracile (50 sites)—both widespread synanthropic species. Three other non-native species were also found. Among native species, slugs, including semislugs, were widespread but occurred in low numbers, and Pupina sp. occurred in high abundance (mean = 97 individuals/site) at 13 highly watered locations within its native range. Urban snail assemblages were not entirely homogeneous, as assemblages in the north region differed from those in the central and northeast regions. In conclusion, urban snail assemblages in Thailand showed a high degree of biotic homogeneity, in large part due to a native species, S. siamensis, indicating that native synanthropic species can contribute to biotic homogeneity.
... Additionally, the occurrence of D. laeve in the Darjeeling Himalayas may depend upon several factors, including climatic (e.g., precipitation) and land cover variables (e.g., snow cover, elevation, herbaceous vegetation etc.) (Gupta et al. 2023). However, the invasion of D. laeve in different patchy regions of the Darjeeling Himalayas (Gupta et al. 2023) might result from human-mediated passive translocation via the ornamental pet trade, as observed in other areas of the world (Cowie et al. 2008;Vázquez et al. 2018). The potential of being an agricultural pest in similar geographic regions (Gittenberger et al. 2018), possible range expansion due to large suitable habitats (Gupta et al. 2023) and spread through ornamental plant trade and transport make different areas of the Darjeeling Himalayas susceptible to the probable negative impacts of D. laeve invasion. ...
Article
Full-text available
The life history traits of the invasive slug, Deroceras laeve, occurring in the Darjeeling Himalayas, India, were estimated under laboratory conditions using the hatchlings from eggs of field-collected D. laeve. The growth pattern of D. laeve was found to be logarithmic, rapidly increased initially, and reached a stable condition till death. The maximum life span of D. laeve was 138±3.48 days, with slightly higher mortality during the juvenile period, which decreased gradually at older ages. The pre-reproductive period of 37±2.7 days, reproductive period of 100.8±5.2 days, and 5.4±1.72 days post-reproductive period of D. laeve were observed. D. laeve attained sexual maturity during 38±2.7 days, and the agespecific fecundity increased with increasing age. The hatchability of the eggs was observed to be >75% following the incubation period of 14.25±0.49 days. The net reproductive value (R0), generation time (Tc), and finite rate of increase (λ) were 40.01, 12.48 weeks, and 1.455, respectively. Apparently, the earlier sexual maturity, high net reproductive rate, and shorter generation time of D. laeve are indicative of its invasive nature as well as prospective range expansion in similar geographic locations.
... It has since then invaded the whole inter-tropical area (Glaubrecht and Salcedo-Vargas 2000), including Benin and Cote d'Ivoire. Melanoides tuberculata is known to be a major pest in horticulture, particularly in areas where it is not native (Cowie et al. 2008). One of the main activities around the Reservoir No.3 of Ouagadougou is horticulture. ...
Article
Full-text available
Human land-use plays an important role in the distribution of aquatic invasive species. The establishment of these species may have an unpredictable impact on their new environment. We analyzed the establishment of M. tuberculata, an invasive species, and its effect on the mollusc community in Ouagadougou's reservoir No.3. Mollusc samples were collected using an Ekman grab through sampling points randomly distributed across the whole reservoir. Collected specimens were sorted, preserved in alcohol at the field site and transported to the laboratory for identification. Species diversity, abundance and distribution were analyzed. Among the five species encountered, M. tuberculata and L. varicus were identified for the first time in this reservoir. M. tuberculata had the highest relative abundance (60.83%) and the highest density. The evenness was less than 0.5 for 72.5% (i.e. 21) of sampling points, reflecting the relative dominance of a single species, M. tuberculata. In terms of spatial distribution, the most widespread species in the study reservoir was M. tuberculata, followed by C. aegyptiaca and B. unicolor. M. tuberculata distribution in the reservoir mostly overlaps that of B. unicolor (0.45). Renewed monitoring efforts are needed to better understand the evolution of mollusc species in freshwaters of Burkina Faso to understand species extinction risks as well as the potential use of mollusk diversity measures as water quality indicators.
... The increasing spread of these intermediate and definitive hosts, respectively, due to globalization, are among the reasons for the currently wide distribution of this species of nematode (Kim et al., 2014). The molluscs that act as intermediate hosts have been transported around the world either intentionally or accidentally through various pathways, notably the agricultural and horticultural industries (Cowie et al., 2008). ...
Article
Full-text available
Semperula wallacei (Issel, 1874) is a species of terrestrial slug that occurs in southeast China and the Pacific Basin and is the only species of its genus that occurs beyond the Oriental region and to the east of Wallace’s line in the Australian region, where it has probably been introduced. In this study, we report for the first time S. wallacei as an intermediate host for Angiostrongylus cantonensis (Chen, 1935) based on histological and molecular analyses of slugs from Tuamasaga, Samoa, deposited at the Medical Malacological Collection (Fiocruz-CMM). DNA was obtained from the deparafinized tissues scraped from specimen slides. Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) targeted to the internal transcribed spacer 2 ( ITS2 ) region were carried out using the restriction enzyme Cla I. The RFLP profile observed for our larval specimen of S. wallacei was identical to the profile previously established for A. cantonensis , demonstrating that S. wallacei can be naturally infected with A. cantonensis and is likely to be an intermediate host for this parasitic nematode species in the field. The potential for geographical range expansion of S. wallacei in the Pacific Basin, its small size, and the general role of veronicellids as crop pests and hosts of nematodes, indicate the significance of S. wallacei as an invasive species in the Pacific Basin. Our work also highlights the importance of biological collections for investigating the environmental impact of invasive species on agriculture, public health, and biodiversity conservation.
... As noted by Speiser (2001) and Bailey & Wedgwood (1991) , direct observation using time-lapse is the most straightforward method to determine the feeding behaviour and food preferences of land gastropods. All five land gastropod species recorded in this study were common urban species, and all are not native to Malaysia (Lim & Heyneman, 1965 ) but are also found worldwide (Cowie et al. , 2008 ;Raheem et al. , 2014 ;Nurinsiyah et al. , 2016 ). These species are typically known to feed on plant matter, fruits and other forms of organic waste, and are known as agricultural pests. ...
Article
Urban land gastropods, snails and slugs, particularly introduced species, are notorious for causing damage to crops and plants. They are also known for their adaptability and ability to survive in unlikely environments, often feeding on other invertebrates and animal faeces (Speiser, 2001). Despite this, their roles as scavengers on animal carcasses have received relatively little attention in the feeding ecology of land molluscs and forensic science (Galvão et al., 2015). Previous observations of land gastropods scavenging on animal carcasses have been opportunistic and limited to a single point in time. Our knowledge of possible interactions with other species, particularly other land molluscs, and feeding activity patterns, including scavenging on carcasses at different stages of decomposition, remains poor. Although the scavenging behaviour of land gastropods on animal carcasses is known (Graham, 1955; Zamora & Gomez, 1996), data are available only for particular mollusc species scavenging on animal carcasses, mainly amphibians (Tan, Lim & Chua, 2015; Pustilnik, 2020; Yadav et al., 2021; Ayres, 2022; Kalki, Rittenburg & Pierson, 2022). While snails have been recorded on mammalian carcasses, the exact roles of these snails are not well understood (Payne, 1965; Galvão et al., 2015).
... Sometimes succineid snails inhabit human-related habitats, such as gardens and fields, and are recorded as introduced species (Holyoak et al. 2013;Benocci et al. 2014). They are increasingly being transported worldwide in the horticultural trade (Cowie et al. 2008). Many species of the family have been described worldwide, in most cases, based only on their shell characteristics (Benocci et al. 2014). ...
... Invasive species both cause economic damage (Pimentel et al. 2005;Gall and Tooker 2017) and threaten native species (Didham et al. 2007;Pejchar and Mooney 2009;Butchart et al. 2010). Today they are spreading at an increasing rate (Seebens et al. 2017;Gladstone et al. 2020), likely because of global climate change (Hellmann et al. 2008;Mainka and Howard 2010) and increased international transportation, especially of agricultural and horticultural products (Meyerson and Mooney 2007;Cowie et al. 2008;Hulme 2009; for reviews, see Peltanová et al. 2012 andPyšek et al. 2020). Transportation as a means of species introduction is especially important for terrestrial molluscs (Bergey et al. 2014), which otherwise have low vagility. ...
Article
Full-text available
Five terrestrial slug species are reported from Hungary, either for the first time or confirming earlier records that had been considered unreliable: Limacus maculatus, Deroceras invadens, Ambigolimax valentianus, Ambigolimax parvipenis, and Milax nigricans. In all cases identification was supported by anatomical examination and barcoding sequences of the COI mitochondrial gene. For M. nigricans we also sequenced individuals of this species from Italy and France so as to establish differences to sequences of M. gagates. Most records came from garden centres in Budapest and from two botanical gardens; these habitats may therefore be crucial in the spreading of non-indigenous species. A Facebook appeal was used to involve citizen scientists in searching for further sites for L. maculatus, but the Limacus populations reported proved all to be L. flavus. Studies over the last four years have added altogether seven slug species to the 26 hitherto recognised in the Hungarian fauna. This demonstrates the importance of continuing to check for additional introduced species.
... O mesmo é verificado para os gastrópodes, os quais têm sido amplamente negligenciados na literatura sobre controle de pragas, apesar de algumas espécies serem importantes pragas e intratáveis ameaças à agricultura sustentável (BARKER, 2001;2002). Várias formas de introdução de espécies exóticas têm sido apontadas, entre elas a indústria agrícola, de forma acidental ou intencional (COWIE & ROBINSON, 2003;COWIE et al., 2008). ...
... Nevertheless, non-native slugs may pose serious threats to established biodiversity by altering established habitats and species composition, disrupting food webs, and causing species loss (Cowie et al. 2008;Jiang et al. 2022). In Nova Scotia, Canada, some non-native slugs are now dominant in forested areas where they have been observed feeding on atrisk lichens (Cameron 2009). ...
Article
Full-text available
Slugs are fungivores, herbivores, carnivores and decomposers that provide important ecosystem services and disservices in natural and disturbed habitats. Our aim was to estimate the effects of local vegetation structure (tree basal area and canopy openness) and landscape composition (land cover types) on the occurrence of native and non-native slugs in 13 cool-temperate forested wetlands across Nova Scotia, Canada. We collected 1437 slugs of eight species (five non-native species and three native species). The non-native Arion subfuscus and Arion fuscus were dominant, and together represented 84.3% of all the slugs collected. The native Deroceras laeve and the non-native Arion hortensis were also relatively common. Among Arion species A. subfuscus was positively associated with open wetlands within a 1000 m radius, whereas A. fuscus and A. hortensis were positively associated with road density within 250 and 750 m radii, respectively. The native species Deroceras laeve and Pallifera dorsalis did not respond to local vegetation and landscape composition. These findings suggest that forested wetlands across Nova Scotia are dominated by non-native Arion species that benefit from road systems and non-forested habitats in the surrounding landscape. The absence of effect on the native species D. laeve and P. dorsalis suggests these species can forage in multiple mainly forested habitats that were the dominant land use types in the studied landscapes. Such information is crucial to fill knowledge gaps and support priority actions for tackling biological invasions at appropriate spatial scales.
... Anthropogenic habitats, notably horticultural establishments such as botanical gardens or plant nurseries, are important pathways for the introduction and establishment of allochthonous land snail species (e.g. Horsák et al., 2004;Cowie et al., 2008;Bergey et al., 2014;Richling & Proschwitz, 2021), even ones new to science (Verdcourt, 1974;Manganelli et al., 2022). A remarkable number of these alien snails are subulinin species, and several records of their presence in Europe exist (e.g. ...
Article
The first record in Malta, and the second record in Europe, of the tropical terrestrial gastropod Paropeas achatinaceum (L. Pfeiffer, 1846) is presented, with an annotated bibliography of the allochthonous (and non-marine) gastropod fauna hitherto recorded from the Maltese archipelago.
... Among the terrestrial molluscs, Darrigran et al. (2020) considered the slug Sarasinula plebeia (Fischer, 1868) a cryptogenic species. However, Gomes and Thomé (2004) considered there to be a consensus that it was introduced into Australia and the several islands on the Pacific by commerce in the Indian and Pacific Oceans and that it is probably originally from tropical areas of America, as also stated by Cowie et al. (2008). Daglio et al. (2020) noted that Vaginula behni Semper, 1885, which is currently a synonym of S. plebeia according to Thomé (1993), was originally described based on material from Rio de Janeiro, Brazil, indicating that it has been present in South America for a long time, despite being originally described based on material from New Caledonia, in the Pacific region. ...
Article
Full-text available
Limnoperna fortunei, a problematic freshwater invasive mussel in South America, was first detected in 1991 at Bagliardi Beach, Río de la Plata (Argentina). Since then, there has been a high increase in population density, reaching up to 150,000 ind. m−2. The distribution, density, individual sizes, and associated mollusk assemblages of L. fortunei were evaluated 30 years after its first detection. Seven sites along Río de la Plata River were sampled between 2018 and 2020. The highest density was recorded in the La Balandra Beach (above the stabilization value) and the lowest density in the Martín García Island (IMG—by its acronym in Spanish—, below the stabilization value). Two reproductive events were observed: late spring and late summer. Our results showed different sets of species associated with Limnoperna fortunei, with protected areas such as the IMG standing out, showing greater species richness, including first records, versus other coastal environments. We recommend increasing conservation efforts given the constant advance of urbanization in the coastal sites of the province of Buenos Aires, with environmental impact studies prior to coastal reforms, and implementation of density control strategies for Limnoperna fortunei in protected areas.
... Among the terrestrial molluscs, Darrigran et al. (2020) considered the slug Sarasinula plebeia (Fischer, 1868) a cryptogenic species. However, Gomes and Thomé (2004) considered there to be a consensus that it was introduced into Australia and the several islands on the Pacific by commerce in the Indian and Pacific Oceans and that it is probably originally from tropical areas of America, as also stated by Cowie et al. (2008). Daglio et al. (2020) noted that Vaginula behni Semper, 1885, which is currently a synonym of S. plebeia according to Thomé (1993), was originally described based on material from Rio de Janeiro, Brazil, indicating that it has been present in South America for a long time, despite being originally described based on material from New Caledonia, in the Pacific region. ...
Article
Full-text available
The movement of species is among the most serious environmental threats of the new millennium, as the transplantation of species beyond their native or historical range has intensified in the last five decades. Traditionally, studies on bioinvasions have focused on species that have been introduced, deliberately or accidentally, to biogeographic regions where they did not previously occur. However, less attention has been given to species movement to novel areas within the same biogeographic region. Our research group, the South America Introduced Molluscs Specialists, analyzed potential cases of native South American mollusc species introduced deliberately or accidentally beyond their natural range within South America. To achieve this, it is key to differentiate between anthropogenic processes and passive responses to environmental conditions. We considered the past and current spatial distribution of species, analyzed known or putative vectors, and discuss the impacts of taxonomic and nomenclatural knowledge. Based on the evidence currently available, we propose different scenarios to explain observed changes in mollusc distributions within South America. Seventeen transplanted mollusc species (TMS) were recognized, considering marine, freshwater, and terrestrial environments. Of the 189 South American ecoregions 31 were occupied by transplanted species, but this proportion varied by environment: 10 of 28 marine ecoregions, 12 of 52 freshwater ecoregions, and 9 of 109 terrestrial ecoregions. The ecoregions with TMS are generally located in the peripheral zones of the continent. Those with the highest number of TMS were the Southern Caribbean (three species) in the marine environment, the Central Andean Pacific Slopes (three species) in the freshwater environment, and the Alto Paraná Atlantic forests (two species) in the terrestrial environment. The number of unintentionally moved TMS is greater than those moved intentionally. The transplantation process is similar to the introduction and settlement process of non-native mollusc species, and so is their impact.
... Despite their slow mobility, the land snail and slugs (Mollusca: Gastropoda) are found to be invaded and established in newer geographic areas [8,9], often with human-assisted dispersal and by hitchhiking with international trade of ornamental pets and plants [10,11]. Worldwide, many introduced snails and slugs have been considered serious pests of agriculture and horticulture [12], have a high parasitic load [13,14], and many are generalist herbivores, exerting high grazing pressure on different ecosystems [12,[15][16][17]. ...
Article
Invasive slugs are a menace from the agricultural point of view apart from the impact on the native biota and the ecosystems. Subsequent to the observations of the marsh slug, Deroceras laeve in West Bengal, India, an attempt was made to confirm the species identity and the species distribution modelling considering the Himalayas of West Bengal and adjacent regions as the geographical distribution of the species. Assessment of the DNA barcoding of the COI gene confirmed the species as D. laeve with 99.84% similarity with a specimen of Canada. Owing to its record from the concerned regions, the prospective spread and the invasion of the species in similar regions were modelled using Maxent species distribution modelling. The result of species distribution modelling indicated that precipitation seasonality, precipitation of the driest month, snow coverage, elevation, and herbaceous vegetation had the most influence on the occurrence of D. laeve. The possible spread of the species can be expected in the future if congenial conditions are available in the extended geographical regions. As an invasive species, D. laeve may affect agricultural productivity apart from altering the habitat conditions and imposing competitive interactions with the native species. Based on the present observation, appropriate strategies may be framed for monitoring and regulating the spread of the invasive slug.
... For example, in California, it is estimated that there are approximately 279 species of terrestrial gastropods, 37 of which are invasive (Roth and Sadeghian, 2003). These gastropods were likely introduced via the horticultural trade when gastropods residing on plant products were delivered to western states (Cowie et al., 2008;Bergey et al., 2014). Some of these introduced gastropods are considered among the most pestiferous slugs and snails. ...
Article
Full-text available
Three species of Phasmarhabditis were recovered from 75 nurseries and garden centers in 28 counties in California during fall and winter 2012–2021. A total of 18 mollusk species were recovered, most of them invasive. Nematodes were identified by sequencing the D2-D3 expansion segments of the large subunit (LSU or 28S) rRNA. Based on these surveys, P. californica was the most widespread species (37 isolates, 53.6% recovery); followed by P. hermaphrodita (26 isolates; 37.7% recovery); P. papillosa and a closely related P. papillosa isolate (6 isolates; 8.7% recovery). Nematode isolates were mainly collected from four invasive slugs (Deroceras reticulatum, D. laeve, Arion hortensis agg, Ambigolimax valentianus) and snails (Oxychilus spp. and Discus spp.). Results suggest that P. californica and P. hermaphrodita share an ecological niche in Northern, Central, Coastal, and Southern California, north of Los Angeles County.
... However, several species of terrestrial mollusks have been introduced to these islands, most likely by human activities such as plant nursery trade (e.g., Hirano et al., 2019d). In fact, approximately 100 species of terrestrial mollusks worldwide appear to be particularly well-adapted to environmental changes brought about by human activity, and often become highly abundant and characteristic components of invertebrate fauna in modified habitats (Barker, 2001;Cowie et al., 2008;Richling & von Proschwitz, 2021) and have the potential to invade new areas. ...
Article
Full-text available
Reliable identification of species is important for protecting native ecosystems against the invasion of non-native species. DNA barcoding using molecular markers, such as the mitochondrial cytochrome oxidase subunit 1 (COI) gene, helps researchers distinguish species. In this study, we focused on introduced veronicellid slugs in the Ryukyu Islands and some greenhouses on mainland Japan. Some veronicellids are medium-to-high risk pest species for humans. Identifying veronicellid species by their external morphology is difficult and unreliable because there is substantial overlap between intraspecific variation and interspecific differentiation. Therefore, internal morphologies such as male genitalia have been the primary traits used to distinguish veronicellids. To identify introduced veronicellid slugs in Japan to the species level, we used morphological assessment of male genitalia and DNA barcoding of the standard COI gene fragment. We also conducted species-delimitation analyses based on the genetic data. The results showed that five evolutionarily significant units, corresponding to four nominal species inhabit the Ryukyu Islands, of which two species were also found in the greenhouses of mainland Japan, including the first record of Sarasinula plebeia in Japan. The presence of non-native slug species could increase the transmission of parasites in Japan.
... Despite these critical ecological impacts, there remains a significant lack of information on economic costs caused by invasive terrestrial invertebrates other than a preliminary estimation of US$70 billion per year for insects in goods and services damages globally (Bradshaw et al., 2016). Some well-known examples of damaging invasive invertebrate groups other than insects include terrestrial gastropods (Cowie et al., 2008), earthworms (Hendrix, 2006) or flatworms (Sugiura, 2010). Nevertheless, the overall economic costs of these reported taxa, and that of invasive terrestrial invertebrates in general, is still lacking. ...
Article
Full-text available
Invasive alien species (IAS) are a major driver of global biodiversity loss, hampering conservation efforts and disrupting ecosystem functions and services. While accumulating evidence documented ecological impacts of IAS across major geographic regions, habitat types and taxonomic groups, appraisals for economic costs remained relatively sparse. This has hindered effective cost-benefit analyses that inform expenditure on management interventions to prevent, control, and eradicate IAS. Terrestrial invertebrates are a particularly pervasive and damaging group of invaders, with many species compromising primary economic sectors such as forestry, agriculture and health. The present study provides synthesised quantifications of economic costs caused by invasive terrestrial invertebrates on the global scale and across a range of descriptors, using the InvaCost database. Invasive terrestrial invertebrates cost the global economy US712.44billionovertheinvestigatedperiod(upto2020),consideringonlyhighreliabilitysourcereports.Overall,costswerenotequallydistributedgeographically,withNorthAmerica(73 712.44 billion over the investigated period (up to 2020), considering only high reliability source reports. Overall, costs were not equally distributed geographically, with North America (73%) reporting the greatest costs, with far lower costs reported in Europe (7%), Oceania (6%), Africa (5%), Asia (3%), and South America (< 1%). These costs were mostly due to invasive insects (88%) and mostly resulted from direct resource damages and losses (75%), particularly in agriculture and forestry; relatively little (8%) was invested in management. A minority of monetary costs was directly observed (17%). Economic costs displayed an increasing trend with time, with an average annual cost of US 11.40 billion since 1960, but as much as US$ 165.01 billion in 2020, but reporting lags reduced costs in recent years. The massive global economic costs of invasive terrestrial invertebrates require urgent consideration and investment by policymakers and managers, in order to prevent and remediate the economic and ecological impacts of these and other IAS groups.
... Some of the invasive plants are introduced intentionally around the world for anthropogenic use, and the fact is that half of the species introduced for ornamental purposes have became invasive over time (Hulme 2009b;Morais et al. 2017). Several studies have recommended the incorporation of horticulture and related industries in research, and it is necessary to manage invasive species through the promotion of the greater use of native flora for ornamentals, fruits, and wood (Reichard and White 2001;Cowie et al. 2008;Van Kleunen et al. 2018). ...
Article
It is generally accepted that urbanisation is changing the composition of species, mostly in urban and surrounding areas, through intentional introduction. The South African National Status Report of 2017 on biological invasions has shown that there is a dearth of knowledge about the invasion status of many invasive alien species in many parts of the country, such as the critically threatened vegetation, Woodbush Granite Grassland (WGG) in Limpopo Province. Consequently, the present study investigated the status of alien plants species in WGG. A roadside survey was carried out in Haenertsburg Village and its vicinity. Roads were used as survey units, and the dumpsite was used as a high risk area. A total of 136 species were identified, belonging to 46 botanical families. This study report the occurrence of 72 species which are regulated by the South Africa’s National Environmental Management: Biodiversity Act (NEMBA, Act 10 of 2004). The present study found results significantly different from existing databases (χ2 =16.33473, p = .0001). Included in our list are alien species that need urgent eradication: Coreopsis lanceolata L., Cytisus scoparius (L.) Link, Iris pseudacorus L., Pueraria montana (Lour.) Merr, -and Rubus species as NEMBA category 1a species. Illegal dumping of agricultural waste was found to be one of the contributing factors to IAS in the area. Our study shows that Woodbush Granite Grassland is facing a new threat from invasive species.
... This finding suggests at least two different introductions of R. decollata into Argentina, one from southern France, and one from the Iberian Peninsula. To date, the introduction pathway of R. decollata into Argentina remains uncertain but could be related to inadvertent human transport, possibly in association with the commerce of ornamental plants and the horticultural trade (Cowie and Robinson 2003;Cowie et al. 2008). The Misiones province is located in the northeastern corner of Argentina, bordering on Brazil and Paraguay. ...
Article
Full-text available
The decollate land snail Rumina decollata (Linnaeus, 1758), native to the Mediterranean region, has been introduced across several countries worldwide. We report here three new records for R. decollata in Argentina, two from Córdoba Province and the first one from Misiones Province, which also constitutes the northernmost record for the country, extending its northeastern distribution range. Species-specific identification was achieved based on anatomical, conchological, and molecular information. DNA data showed that different haplotypes are present in Argentina, which originated from distinct source areas along the native range.
... O mesmo é verificado para os gastrópodes, os quais têm sido amplamente negligenciados na literatura sobre controle de pragas, apesar de algumas espécies serem importantes pragas e intratáveis ameaças à agricultura sustentável (BARKER, 2001;2002). Várias formas de introdução de espécies exóticas têm sido apontadas, entre elas a indústria agrícola, de forma acidental ou intencional (COWIE & ROBINSON, 2003;COWIE et al., 2008). ...
... In this process, many species have become endangered, sometimes because of other mollusk pest biological control efforts (Lydeard et al., 2004). Other terrestrial gastropod species have benefited from human-facilitated dispersal, and have become invasive pests (Cowie et al., 2008). This was observed early on by Binnei (1871), when he described "All the species mentioned below are of foreign origin. ...
Article
Full-text available
Slugs can be important agricultural pests in tropical regions. They are also intermediate hosts of parasitic nematodes, such as Angiostrongylus costaricensis and A. cantonensis , which can cause abdominal and cerebral angiostrongyliasis in humans. Management of slugs in conventional agriculture has relied heavily in the use of pellets containing metaldehyde. In this article, we review cases of slug problems and their management in neotropical agroecosystems.
... At the same time, there remains a signi cant lack of information on economic costs caused by invasive terrestrial invertebrates other than insects, which early estimation was of US$70 billion per year in goods and services damages globally (Bradshaw et al. 2016). Some well-known examples of damaging invasive invertebrate groups other than insects include terrestrial gastropods (Cowie et al. 2008), earthworms (Hendrix 2006) or atworms (Sugiura 2010). Nevertheless the overall economic costs of these taxa and of invasive terrestrial invertebrates have not been assessed so far. ...
Preprint
Full-text available
Invasive species are a major driver of global biodiversity loss, hampering conservation efforts and disrupting ecosystem functions and services. While accumulating evidence has documented ecological impacts of invasive species across major geographic regions, habitat types and taxonomic groups, appraisals for economic costs have remained relatively sparse. This has hindered effective cost-benefit analyses that inform expenditure on management interventions to prevent, control, and eradicate invasive species. Terrestrial invertebrates are a particularly pervasive and damaging group of invaders, with many species compromising primary economic sectors such as agriculture and health. The present study provides synthesised quantifications of economic costs caused by invasive terrestrial invertebrates on the global scale and across a range of descriptors, using the InvaCost database. Invasive terrestrial invertebrates reportedly cost the global economy US1.26trillionovertheinvestigatedperiod(19602020),mostlyduetoinvasiveinsects(>90 1.26 trillion over the investigated period (1960–2020), mostly due to invasive insects (> 90%). Overall, costs were not equally distributed geographically, with North America (76%) reporting the greatest costs, with far lower costs reported in Europe (4%) Asia (4%), Africa (3%), South America (2%), and Oceania (1%). These costs mostly resulted from direct resource damages and losses (76%), particularly to agriculture and forestry; relatively little (4%) was invested in management. A minority of monetary costs was directly observed (43%), but costs were mostly sourced from highly reliable estimates (58%). Economic costs displayed an increasing trend with time, with an average annual cost of US 20.67 billion since 1960, but reporting lags reduced costs in recent years. The massive global economic costs of terrestrial invertebrates require urgent consideration and investment by policymakers and managers, in order to prevent and remediate the economic and ecological impacts of these and other invasive species groups.
... As a result, relatively low levels of dispersal limitation can be expected within a local region, making it more likely that observed pattern is related to ecological process and not historical contingency. The excellent passive dispersal abilities of land snails have also helped them rapidly spread through the global anthropogenic landscape (Robinson 1999), with their typical entry into urban yards (Hodges and McKinney 2018;Bergey 2019) by the horticultural trade (Cowie et al. 2008;Bergey and Figueroa 2016). ...
Article
Full-text available
A noted impact of urbanization is the tendency for biotic homogenization, or the increase of similarity of geographically disparate communities. On the other hand, some urban habitats harbor biodiversity native to their region, a role potentially important in xeric landscapes, with irrigation increasing the coverage and availability of mesic habitats in an otherwise water-limited landscape. We assessed the relative importance of urban yards as agents of biotic homogenization or riparian refugia by characterizing community composition of Tamaulipan thornforest land snail assemblages across a pronounced precipitation gradient in far south Texas, USA. We quantified α- and β-diversity and assessed whether the land snail fauna of urban yards are more similar to each other across a precipitation gradient than they are to their wild counterparts, as well as determined the significance of moisture in driving Tamaulipan thornforest β-diversity, both in terms of turnover (changing species composition) and nestedness (species loss). Sites with both the wild and wet conditions had the highest values of species richness and abundance. Urban land snail communities were significantly homogenized, outweighing the influence of the precipitation gradient. We did not find urban yards served as a refuge for native, moisture-dependent, riparian snails. Our analyses find that turnover, not nestedness, is the largest contributor to β-diversity in these assemblages. Studies of urbanization should address regional spatial scales to quantify how urbanization modifies regional biodiversity arising from background environmental gradients. Such an approach could lead to improved understanding of how large metroplex areas could be used to maintain and even promote biodiversity.
... Within 3 years 12,000 were collected from these areas and distributed to establish populations throughout Oahu and on other Hawaiian Islands (Kauai, Maui and Hawaii) and elsewhere (Davis and Butler 1964). Populations were also established on Molokai, and it was reported on Lanai by Cowie et al. (2008), with an established population recorded in 2018 (Yeung et al. pers. obs.). ...
Article
Full-text available
Since 1955 snails of the Euglandina rosea species complex and Platydemus manokwari flat-worms were widely introduced in attempted biological control of giant African snails (Lissachatina fulica) but have been implicated in the mass extinction of Pacific island snails. We review the histories of the 60 introductions and their impacts on L.fulica and native snails. Since 1993 there have been unofficial releases of Euglandina within island groups. Only three official P. manokwari releases took place, but new populations are being recorded at an increasing rate, probably because of accidental introduction. Claims that these predators controlled L. fulica cannot be substantiated; in some cases pest snail declines coincided with predator arrival but concomitant declines occurred elsewhere in the absence of the predator and the declines in some cases were only temporary. In the Hawaiian Islands, although there had been some earlier declines of native snails, the Euglandina impacts on native snails are clear with rapid decline of many endemic Hawaiian Achatinellinae following predator arrival. In the Society Islands, Partulidae tree snail populations remained stable until Euglandina introduction, when declines were extremely rapid with an exact correspondence between predator arrival and tree snail decline. Platydemus manokwari invasion coincides with native snail declines on some islands, notably the Ogasawara Islands of Japan, and its invasion of Florida has led to mass mortality of Liguus spp. tree snails. We conclude that Euglandina and P. manokwari are not effective biocontrol agents, but do have major negative effects on native snail faunas. These predatory snails and flatworms are generalist predators and as such are not suitable for biological control.
... Within 3 years 12,000 were collected from these areas and distributed to establish populations throughout Oahu and on other Hawaiian Islands (Kauai, Maui and Hawaii) and elsewhere (Davis and Butler 1964). Populations were also established on Molokai, and it was reported on Lanai by Cowie et al. (2008), with an established population recorded in 2018 (Yeung et al. pers. obs.). ...
Article
Full-text available
Since 1955 snails of the Euglandina rosea species complex and Platydemus manokwari flat-worms were widely introduced in attempted biological control of giant African snails (Lissachatina fulica) but have been implicated in the mass extinction of Pacific island snails. We review the histories of the 60 introductions and their impacts on L.
... Within 3 years 12,000 were collected from these areas and distributed to establish populations throughout Oahu and on other Hawaiian Islands (Kauai, Maui and Hawaii) and elsewhere (Davis and Butler 1964). Populations were also established on Molokai, and it was reported on Lanai by Cowie et al. (2008), with an established population recorded in 2018 (Yeung et al. pers. obs.). ...
Article
Full-text available
Since 1955 snails of the Euglandina rosea species complex and Platydemus manokwari flatworms were widely introduced in attempted biological control of giant African snails (Lissachatina fulica) but have been implicated in the mass extinction of Pacific island snails. We review the histories of the 60 introductions and their impacts on L. fulica and native snails. Since 1993 there have been unofficial releases of Euglandina within island groups. Only three official P. manokwari releases took place, but new populations are being recorded at an increasing rate, probably because of accidental introduction. Claims that these predators controlled L. fulica cannot be substantiated; in some cases pest snail declines coincided with predator arrival but concomitant declines occurred elsewhere in the absence of the predator and the declines in some cases were only temporary. In the Hawaiian Islands, although there had been some earlier declines of native snails, the Euglandina impacts on native snails are clear with rapid decline of many endemic Hawaiian Achatinellinae following predator arrival. In the Society Islands, Partulidae tree snail populations remained stable until Euglandina introduction, when declines were extremely rapid with an exact correspondence between predator arrival and tree snail decline. Platydemus manokwari invasion coincides with native snail declines on some islands, notably the Ogasawara Islands of Japan, and its invasion of Florida has led to mass mortality of Liguus spp. tree snails. We conclude that Euglandina and P. manokwari are not effective biocontrol agents, but do have major negative effects on native snail faunas. These predatory snails and flatworms are generalist predators and as such are not suitable for biological control.
... Cumulative effects of demography and migration and recreation and tourism with the subsequent development of infrastructure (e.g., roads and hiking trails; Haider et al., 2018;Liedtke et al., 2020) might foster future establishment of alien species as these structures have been shown to be introduction pathways (Toral-Granda et al., 2017). Additionally, cultivation of alien species near tourist accommodations and in public green spaces further increases the probability that these species might jump the fence and establish new populations outside gardens (Cowie et al., 2008;van Kleunen et al., 2018). In several instances, charismatic alien species have as well adopted an economic value for the local community because they attract tourists (Jarić et al., 2020). ...
Article
Full-text available
Biological invasions are a major threat to global biodiversity with particularly strong implications for island biodiversity. Much research has been dedicated towards understanding historic and current changes in alien species distribution and impacts on islands and potential changes under future climate change. However, projections of how alien species richness and impacts on islands might develop in the future are still lacking. In the absence of reliable projections, expert-based assessments are a valuable tool to investigate the importance of different drivers and pathways and the distributions of potential impacts of future biological invasions. These insights can guide subsequent quantification efforts and inform invasive species management and policy. In this study, we performed a survey among 126 experts in invasion science ranging from scientists to managers and decision makers with a focus on island systems until the mid-21st century. The survey revealed that out of 15 drivers, six were considered important by almost all respondents (>90%). Of these, trade and transport was identified as most important at the introduction stage (99.2%) and land use/cover change as most important at the establishment (96.8%) and spread (95.2%) stage. Additionally, the experts considered that alien species were more likely to be introduced (93.7%) and spread (78.6%) as stowaways than through any other pathway. In general, respondents agreed that the impacts of alien species will increase on all types of islands, particularly on oceanic islands, followed by atolls and continental islands. Within islands, terrestrial ecosystems were assumed to be impacted more severely than marine ecosystems. Finally, the survey hints toward the potential for effective communication, scientific research and increased pro-active management of alien species on islands to reduce their future consequences. Given the major threat represented by invasive alien species on islands, these results provide crucial insights relevant for global and regional conservation efforts.
... Snail populations in urban areas can be quite speciose, comprised of both local native species and a suite of non-native species [11,16,21,24,25]. Although snails move slowly on their own, they can be frequent hitch-hikers-dispersing through such routes as the plant trade [24,26,27] or landscaping materials. ...
Article
Full-text available
Residential yards constitute a substantive biodiverse greenspace within urban areas. This biodiversity results from a combination of native and non-native species and can contribute to biotic homogenization. Geographical climatic patterns affect the distribution of native species and may differently affect non-native species. In this study, we examined biodiversity and biotic homogenization patterns of yard-dwelling land snails across 12 towns in Oklahoma and Kansas (USA). The 3 x 4 array of towns incorporated a N-S winter temperature gradient (mean low January temperature range = -8.4 to 0.1°C) and an E-W annual rainfall gradient (annual rainfall range = 113.8 to 61.3 cm/yr). Ten yards per town were surveyed. We hypothesized that mild winter temperatures and greater annual rainfall would be associated with greater snail abundance and richness, and that the presence of non-native species would contribute to biotic homogenization. Non-native snails were present and often abundant in all towns. Snail communities varied with both rainfall and cold temperature. Contrary to our prediction, snail abundance was inversely related to annual rainfall–likely because drier conditions resulted in greater yard watering that both augmented rainfall and maintained moist conditions. Sørensen similarity between towns for the entire land snail community and for only non-native species both showed distance-decay patterns, with snail composition becoming less similar with increasing distance—patterns resulting from species turnover. The biotic homogenization index also showed a distance-related pattern, such that closer towns were more likely to have biotic homogenization whereas more distant towns tended to have biotic differentiation. These results support the concept that biotic homogenization is more likely regionally and that climatic changes over distance result in species turnover and can reduce spatially broad biotic homogenization.
... The time and source of introduction of this parasite into Florida is unknown, but rapidly increasing rates of international travel and commerce are escalating the introduction of non-native species including snails (Robinson, 1999;Cowie et al., 2008) that are potential hosts for A. cantonensis. Many distantly related snail species have been reported as hosts for A. cantonensis (Kim et al., 2014) and snail introductions are common in Florida (Robinson and Slapcinsky, 2005). ...
Article
Full-text available
Angiostrongylus cantonensis has been found in Florida, USA, from the panhandle in the north to Miami and surrounding areas in the southern parts of the state, in both definitive and intermediate hosts in a limited studies completed in 2015. Additional studies have identified this parasite in a variety of intermediate hosts, both native and non-native gastropod species, with new host species recorded. Many areas in Florida with higher A. cantonensis prevalence were those with a high human population density, which suggests it is a matter of time before human infections occur in Florida. Case reports in the state currently involve non-human primates and include a gibbon and orangutan in Miami. Here, we report the current status of A. cantonensis in the state, as well as the infection in a capuchin monkey and presumptive infection in a red ruffed lemur in Gainesville, Florida.
... Later introductions of non-native species by Europeans, including large ungulates, accelerated the loss of native vegetation and led to further changes in Hawaiian ecosystems. These ecosystems continue to be threatened by ongoing transportation of plants and animals around the world, and the number of nonnative species that have become established in Hawaii has exploded, with more than 60 introduced snail species (Cowie et al. 2008, Hayes et al. 2007, 2012 and more than 2,800 established non-native arthropods (Eldredge 2006). ...
Article
Full-text available
Background Arion vulgaris Moquin-Tandon, 1855 is amongst the fastest-spreading terrestrial slugs Europe-wide. In recent years, it has been recorded in Canada, Mexico and continues to expand eastwards into Eurasia. Renowned for its high invasiveness, combatting its swift spread creates significant challenges in organising effective preventative measures. New information This study presents the first record of Arion vulgaris from Armenia, which is the second record of this species' invasion of the Caucasus. In 2022, a substantial population of A. vulgaris was observed close to the City of Stepanavan, which is also the first record in Armenia of the family Arionidae. How the species was introduced to Armenia remains unknown. Identification of Arion vulgaris was conducted, based on external and genital morphology and mitochondrial CO1 (cytochrome c oxidase subunit 1) gene sequencing, revealing notable similarities with Central European clades. Our results confirm the introduction and distribution of A. vulgaris to Armenia. Invasion of such species into Armenia will require additional monitoring and would be aided by further research on Armenia’s mollusc fauna in the future.
Preprint
Full-text available
The multi-billion dollar ornamental plant trade benefits economies worldwide but shifting and more streamlined globalised supply chains have exacerbated complex environmental, sustainability, and biosecurity risks. We review environmental and social costs of this international legal trade, and complement this with analyses of illegal plant trade seizures and plant contaminant interception data from the Netherlands and the UK. We show global increases in ornamental plant trade, with notable supply expansions in East Africa and South America and issues including biodiversity loss, aquifer depletion, pollution, and undermining of access-and-benefit-sharing and food security. Despite risk mitigation, interception data showed considerable volumes of contaminants in ornamental plant shipments, yet taxonomic identification was not always possible, highlighting uncertainties in assessing biosecurity risks. With high-volume and fast-moving transit of ornamental plants around the world, it is essential that standards are improved, and data on specific risks from trade are collected and shared to allow for mitigation.
Article
This datasheet on Veronicella cubensis covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.
Article
This datasheet on Cornu aspersum covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.
Article
Full-text available
Invasive alien gastropods are a particularly pervasive taxonomic group worldwide, often causing substantial impacts on aquatic and terrestrial ecosystems. Yet, much remains unknown about this invasive group’s economic costs to human society. Here, we used the InvaCost database to evaluate the taxonomic, spatial, and temporal patterns of economic costs associated with invasive gastropods on the global scale. In total, 13 species of invasive gastropods caused a cumulative global cost of US3.94billionovertheperiod19662020,withamajoritybeingattributedtoaquaticspecies( 3.94 billion over the period 1966–2020, with a majority being attributed to aquatic species ( 3.72 billion, 94.4 %, concentrated mostly in Asia) and only $ 0.22 billion (5.6 %, concentrated mostly in Europe) to terrestrial species. Among different regions, Asia (3.71 billion) reported the greatest costs, compared to far lower costs reported in Europe (214.50 million), North America (13.80 million), Oceania (2.69 million), South America (
Book
Full-text available
Hawai'i's Invasive Species describes the causes and consequences of the introduction of invasive alien species of plants and animals to the Hawaiian Islands. Almost a hundred species are covered in detail, illustrating the negative impacts of invasive alien species on human health and quality of life, agriculture, commerce, and the environment. Anyone interested in the natural world, both Island residents and visitors, will find this compact book filled with interesting - and alarming - information. Written by a team of experts from the Hawaii Biological Survey, Hawai'i's Invasive Species is an authoritative and accessible account of the problems invasive alien species cause on Islands.
Article
Full-text available
With the expanding global economy, increasing trade volume and international trade agreements facilitating commodity movements worldwide, the risks of "alien" introductions are increasing. Of over 4,900 molluscan interceptions from almost 100 countries by USDA APHIS PPQ over the last five years on commodities entering the United States, some 369 gastropod taxa, belonging to 197 genera in 71 families, have been identified. Although expected on agricultural and horticultural products, "hitch-hikers" also are found in and on shipping containers, household tiles, military hardware, aquarium supplies, and other items, as well as being deliberately introduced. Many of the mollusks belong to a lengthened list of traveller species, and the number of travelling species in each species is increasing inexorably despite efforts to slow their invasions. A listing of these travelling species is given, together with their distributions in the principal regions of the world with which the United States has commerce. This is drawn from a survey of the world malacological bibliography, which is provided. Most countries lack or have minimal quarantine restrictions, or where inspection agencies exist, they may be ineffective and/or underfunded. Local agriculture potentially will be negatively affected, native species adversely impacted, and the establishment of a non-indigenous species will create a reservoir for its further spread when that country exports its own products abroad. These invasive species may also be human and livestock disease vectors. As we lack specific ecological information for most of these taxa, there is an urgent need for the collection and pooling of any such data from concerned scientists and governments worldwide.
Article
Full-text available
The number of alien species of terrestrial molluscs in North America continues to increase despite existing quarantine barriers. The effects of non-indigenous species on agriculture, horticulture or the environment have yet to be ascertained, but are potentially serious. We report the recent introduction of seven species of terrestrial species into North America. Three Eurasian species, Monacha cartusiana, Monacha syriaca, and Xerolenta obvia appear to have arrived on shipping containers. The other four species, Beckianum beckianum, Paropeas achatinaceum, Bulimulus tenuissimus puellaris, and Ovachlamys fulgens, were introduced on plant materials, most likely from South and Central America.
Article
Full-text available
The introduced snail Ovachlamys fulgens (Stylommatophora: Helicarionidae) occurs on cultivated land habitats in Costa Rica, where its macrodistribution seems to be limited by annual mean temperature (20 -27.6°C) and annual precipitation (1 530 - 3 034 and 3 420 - 8 000 mm, with no more than six dry months). This species can be found in litter and on vegetation up to 70 cm tall. Random quadrat field sampling was done in leaf Mer and understory plants every three months for a total of five dates in Central Costa Rica. At least 150 plots of 25x25 cm were analyzed on each date. Abundance of living specimens and eggs was positively correlated with (1) litter abundance and depth, (2) litter and soil humidity, (3) relative humidity and (4) early morning temperature (6-30 AM) and negatively correlated with temperature later in the morning (10:00 AM). Besides these factors living snail abundance was correlated with thickness of the herbaceous vegetation and with the occurrence of Yucca elephantiphes (in litter and understory). Egg abundance was also correlated with the sampling date, apparently because of changes in humidity. The correlation pattern of shell abundance was opposite to that of living specimens. Population size and number of empty shells throughout the year parallel the rainfall pattern. Reproduction takes place between May and November (wet season); and up to 92% of the specimens can be found aestivating between December and April (dry season). Clutch size averages three eggs. The maximum density of living specimens was reached in December (43.41 ind/m2) and the minimum in March (8.30 ind/m2). Shells decompose in an average of five months.
Article
Full-text available
ABSTRACT Invading non-indigenous species in the United States cause major environmental damages,and losses adding up to more than $138 billion per year. There are approximately 50,000 foreign species and the number is increasing. About 42% of the species on the Threatened or Endangered species lists are at risk primarily because of non-indigenous species. In the history of the United States, approximately 50,000 non-indigenous (non-native)
Article
Full-text available
About 2,400 names at the rank of subtribe, tribe, subfamily, family and superfamily have been proposed for Recent and fossil gastropods. All names are listed in a nomenclator giving full bibliographical reference, date of publication, type genus, and their nomenclatural availability and validity under the International Code of Zoological Nomenclature. Another 730 names, established for categories above the family-group, and not regulated by the Code, are listed separately. A working classification attempts to reconcile recent advances in the phylogeny of the Gastropoda, using unranked clades above superfamilies, and the more traditional approach, using hierarchical ranking below superfamily. Altogether, the classification recognizes as valid a total of 611 families, of which 202 are known exclusively as fossils and 409 occur in the Recent with or without a fossil record. The nomenclator and classification will be updated in forthcoming editions to be published electronically.
Article
Full-text available
The native snails of the Hawaiian Islands are disappearing. One cause is predation by introduced carnivorous snails. Habitat destruction/modification is also important, facilitating the spread of other non-indigenous snails and slugs. Eighty-one species of snails and slugs are recorded as having been introduced. Thirty-three are established: 12 freshwater, 21 terrestrial. Two or three species arrived before western discovery of the islands (1778). During the nineteenth century about one species per decade, on average, was introduced. The rate rose to about four per decade during the twentieth century, with the exception of an especially large number introduced in the 1950s as putative biocontrol agents against the giant African snail, Achatina fulica. The geographical origins of these introductions reflect changing patterns of commerce and travel. Early arrivals were generally Pacific or Pacific rim species. Increasing trade and tourism with the USA, following its annexation of Hawaii, led to an increasing proportion of American species. More general facilitation of travel and commerce later in the twentieth century led to a significant number of European species being introduced. African species dominated the 1950s biological control introductions. The process continues and is just part of the homogenization of the unique faunas of tropical Pacific islands.
Article
Full-text available
The golden apple snail, Pomacea canaliculata (Lamarck, 1822) (Mesogastropoda: Pilidae), has recently been introduced to several Asian countries where it has unexpectedly developed into a pest of rice. Reasons for the introduction as well as the economic and ecological impact of the snail are described. Most farmers have resorted to chemical control, with implications for human health and the environment. Integrated snail management practices are summarized including the use of the snail as a valuable aquatic resource. It is concluded that research on control strategies is urgently needed but requires sound knowledge of the ecology of the snail in its natural habitat.
Article
Full-text available
The morphology of the two species of Australian freshwater assimineids is described in detail. A new genus and species of Assimineinae, Aviassiminea palitans, is named from freshwater springs in north Western Australia and the Northern Territory. Austroassiminea letha Solem et al., 1982 from coastal springs in south Western Australia is also described and the original anatomical account is corrected in several important details. This taxon is shown to be a member of the Omphalotropidinae and is the only other non-marine assimineid known from Australia. All of the described assimineid genus-group taxa are listed in an appendix, with an assessment of their status, and their known diagnostic characters.
Article
Full-text available
Most commercial products for snail and slug control contain either metaldehyde or methiocarb as the active ingredient, the residues of which are not permitted in food crops in the United States. We have discovered that solutions of caffeine are effective in killing or repelling slugs and snails when applied to foliage or the growing medium of plants. Because caffeine is a natural product and is classified by the US Food and Drug Administration as a GRAS (‘generally recognized as safe’) compound, it has potential as an environmentally acceptable alternative toxicant for the control of slugs and snails on food crops. While field-testing caffeine as a toxicant against an introduced frog pest that infests potted plants in Hawaii, we discovered that large slugs were killed by spray applications containing 1–2% caffeine. To test whether caffeine solutions could be used to remove or kill large slugs that attack potted plants, we allowed Veronicella cubensis (Pfeiffer) to bury themselves in the soil in the pots, and then thoroughly wetted the soil with a 2% caffeine solution. After 3.5 h, only 25% of the slugs remained in the soil; after 48 h, all slugs had left the soil and 92% were dead.
Article
Full-text available
The semi-slug Parmarion cf. martensi Simroth, 1893, was first discovered on O‘ahu, Hawai‘i, in 1996 and then on the island of Hawai‘i in 2004. This species, which is probably native to Southeast Asia, is abundant in eastern Hawai‘i Island, reportedly displacing the Cuban slug, Veronicella cubensis (Pfeiffer, 1840), in some areas. A survey in July–August 2005 found P. cf. martensi primarily in the lower Puna area of Hawai‘i Island, with an isolated population in Kailua-Kona (western Hawai‘i Island). It is now established in commercial papaya plantations, and survey participants reported it as a pest of lettuce and papaya in home gardens. Survey respondents considered P. cf. martensi a pest also because of its tendency to climb on structures where it deposits its feces and because of its potential to transmit disease. Individuals of this species were found to carry large numbers of infective third-stage larvae of the nematode Angiostrongylus cantonensis (Chen, 1935), the causative agent of human angio-strongyliasis and the most common cause of human eosinophilic meningo-encephalitis. Using a newly developed polymerase chain reaction test, 77.5% of P. cf. martensi collected at survey sites were found infected with A. cantonensis, compared with 24.3% of V. cubensis sampled from the same areas. The transmission potential of this species may be higher than that for other slugs and snails in Hawai‘i because of the high prevalence of infection, worm burdens, and its greater association with human habitations, increasing the possibility of human-mollusk interactions.
Article
Full-text available
Over 120,000 non-native species of plants, animals and microbes have invaded the United States, United Kingdom, Australia, South Africa, India, and Brazil, and many have caused major economic losses in agriculture and forestry as well as negatively impacting ecological integrity. Some introduced species, like corn (Zea mays L.), wheat (Triticum spp.), rice (Oryza sativa L.), plantation forests, domestic chicken (Gallus spp.), cattle (Bos taurus), and others, are beneficial and provide more than 98% of the world’s food supply. Precise economic costs associated with some of the most ecologically damaging alien species are not available. Cats (Felis cattus) and pigs (Sus scrofa), for example, are responsible for the extinction of various animal species, however, it is impossible to assign monetary values to species forced to extinction. The estimate is that non-native species invasions in the six nations are causing more than US$ 314 billion per year in damages.
Article
Full-text available
We identify a significant relationship between domestic market-based propagule pressure, as measured both in presence in the British horticultural market and in seed prices of ornamental plant species, with success in invasion. We employ a multispecies temporal approach and use a Generalized Estimation Equation model comparing ornamental non-native species introduced into Britain which started to invade with species introduced but not known outside cultivation. Historical nursery catalogues gave information on the availability and prices of seeds of 506 ornamental species in the British horticultural market every 20 years from 1885 to 1985. Higher market frequency and cheap prices of seeds were more significant and had a greater impact on the invading probability 20 years later than at the date of listing in a nursery catalogue. Our results suggest that national economic factors are an important part of the explanation for the invasiveness of ornamental plant species, and hence for the development of potential solutions.
Article
Full-text available
We investigated the effects of an exotic snail, the golden apple snail (Po-macea canaliculata) on biodiversity and ecosystem functioning in tropical wetland eco-systems. This large snail (up to 80-mm shell height) has invaded large parts of Southeast Asia during recent decades. A survey of natural wetlands in Thailand showed that high densities of the snail were associated with almost complete absence of aquatic plants, high nutrient concentrations, and high phytoplankton biomass, that is, a complete shift in both ecosystem state and function. A field experiment demonstrated that grazing by the snail can cause the loss of aquatic plants, a change toward dominance of planktonic algae, and thereby a shift toward turbid water. Estimates of biologically fixed nutrients released through snails grazing on aquatic plants revealed that phosphorus releases were sufficient to explain the recorded increase in phytoplankton biomass. Hence, our study demonstrates how an herbivore may trigger a shift from clear water and macrophyte dominance to a turbid state dominated by planktonic algae. This shift and the continuing aggressive invasion of this exotic species are detrimental to the integrity and functioning of wetland ecosystems, and to the services these provide in Southeast Asia.
Article
Full-text available
Species richness in a group of caves in the 21.25 km2 corner of the USGS 7 1/2 minute Williamsburg quadrangle, West Virginia, was investigated to (1) increase our knowledge of species richness for this area, (2) determine how many caves need to be sampled to achieve an accurate estimate of species richness and (3) estimate how many species are present in this area. Eighteen subterranean invertebrate species were collected from 65 caves within the study area. Seven caves were needed to collect 95% of the species. By sampling only the largest seven caves, 89% of the species were captured. However, the species accumulation curve did not reach an asymptote, and estimations based on species rarity show that half of the species were not collected at all. Therefore, the observed patterns should be interpreted with caution, and more data are needed.
Article
Full-text available
Introduced slugs have invaded many parts of the world where they were recognized as important pests of gardens and agriculture, but we know little about the effects of introduced slugs on rare plants in natural areas. The Hawaiian Islands have no native slugs, but over a dozen introduced slug species are now established. We reviewed Rare Plant Recovery Plans produced by the U.S. Fish and Wildlife Service for Hawaii and found that introduced slugs were specifically mentioned as threats or potential threats to 59 rare plant species (22% of all endangered and threatened plants), based mainly on anecdotal observations by field biologists. We then initiated an experimental field study to assess the impact of slug herbivory on the growth and survival of two endangered plant species (Cyanea superba, and Schidea obovata), one non-endangered native species (Nestegis sandwicensis) and two co-occurring invasive plant species (Psidium cattleianum and Clidemia hirta). In mesic forest on the Island of Oahu, we tracked the fate of outplanted seedlings in replicated 1 m2 plots, with and without slug control. Slugs decreased seedling survival of the endangered species by 51%, on average. Slugs did not significantly affect survival of the non-endangered or invasive plant species. Introduced slugs seem to be under-appreciated as a direct cause of plant endangerment. Invasive slugs may also facilitate the success of some invasive plant species by reducing competition with more palatable, native plant competitors. Slug control measures are relatively inexpensive and could facilitate rare plant establishment and population recovery.
Article
Full-text available
The giant African snail, Achatina fulica, has been introduced to many parts of Asia as well as to numerous islands in the Indian and Pacific Ocean, and has recently reached the West Indies. It has been widely decried as a disaster to agricultural economies and a threat to human health, leading to a clamor for the introduction of biological control agents. In fact, the lasting impact on agriculture may not be severe, and the human health risk is probably minor. This snail can be an aesthetic atrocity and a nuisance in other ways, however. Wherever A. fulica has achieved high densities, it has subsequently undergone a striking decline. Although this decline has been attributed to introduced predators, there is little evidence for this hypothesis; instead, epizootic disease seems to be at least part of the cause. However, the introduced predators, especially a New World snail, Euglandina rosea, have wrought havoc with the native land snails of many islands. They have already caused many extinctions and will almost certainly cause others. This predator was introduced by government agencies in many areas despite warnings from competent biologists that the effects could be disastrous. Pressures for such actions may become overwhelming in the face of a highly visible invasion, despite policies that should mandate extreme caution.
Conference Paper
With the expanding global economy, increasing trade volume and international trade agreements facilitating commodity movements worldwide, the risks of "alien" introductions are increasing. Of over 4,900 molluscan interceptions from almost 100 countries by USDAAPHIS PPQ inspectors over the last five years on commodities entering the United States, some 369 gastropod taxa, belonging to 197 genera in 71 families, have been identified. Although expected on agricultural and horticultural products, "hitch-hikers" also are found in and on shipping containers, household tiles, military hardware, aquarium supplies, and other items, as well as being deliberately introduced. Many of these mollusks belong to a lengthening list of traveller species, and the number of introduced species in each country is increasing inexorably despite efforts to slow their invasions. A listing of these travelling species is given, together with their distributions in the principal regions of the world with which the United States has commerce. This is drawn from a survey of the world malacological bibliography, which is provided. Most countries lack or have minimal quarantine restrictions, or where inspection agencies exist, they may be ineffective and/or underfunded. Local agriculture potentially will be negatively effected, native species adversely impacted, and the establishment of a non-indigenous species will create a reservoir for its further spread when that country exports its own products abroad. These invasive species may also be human and livestock disease vectors. As we lack specific ecological information for most of these taxa, there is an urgent need for the collection and pooling of any such data from concerned scientists and governments worldwide.
Book
The author tracks the extent and explains the dangers of biological invasions across the globe and places this problem in the context of global change. The mechanisms of invasion are outlined and their contribution to declines in biodiversity is explained. It is shown how bioinvasions are not only destroying ecosystems, but are also endangering human health, disrupting the cultures of traditional forest and fishing peoples, and costing our economies billions of dollars each year. Policies for countering these invasions are outlined, from international legal reform to in-the-field control techniques.
Article
This paper reviews work on aspects of the biology and management of alien non-marine molluscs in the islands of the tropical and subtropical Pacific. Excluding New Zealand, 82 land snail species (including 14 considered cryptogenic-of unknown origin) and 59 alien freshwater species (including 38 cryptogenic species) have been recorded; an additional 17 have been reported from New Zealand. Three alien freshwater bivalves have also been recorded. Larger and better-surveyed islands have more alien species recorded, with Hawaii standing apart as the most heavily invaded, having over 40 established alien snail species. A few species were introduced by Pacific islanders prior to colonization of the islands by Europeans, but the majority were introduced following the arrival of Europeans, and especially during the latter half of the twentieth century. Alien molluscs in the Pacific originate from all over the world, but, at least in Hawaii, the majority of recent introductions are of New World origin. Some were introduced deliberately, primarily as human food resources and as biological control agents. Others were introduced accidentally in association with commerce, most notably the horticultural and agricultural trades. Some species have become agricultural, horticultural, and garden pests; others prey on native snail species and have caused widespread extinctions; and others may be outcompeting native snail species. Many are able to act as vectors of parasites of humans and livestock, and some have become general nuisances. Commercial interests are affected when export shipments (e.g., of horticultural products) are rejected because of contamination by alien snails. Eradication of alien molluscs is rarely possible. Curtailing the further spread and introduction of alien snails in the Pacific depends primarily on adequate quarantine efforts, which must be implemented at three stages: pre port of entry, at port of entry, and post port of entry. At present, such efforts are inadequate or lacking. Educating the public, politicians, and business people is crucial.
Article
Data from 11 land snail surveys undertaken on the islands of the Pacific (Hawaii, American Samoa, Palau) are analyzed in order to ascertain the proportions of species represented in the death assemblage alone or the live assemblage alone, and whether the abundances of the individual species in the two assemblages are correlated. The percentage of species collected only as dead shells ranged from 13 % to 52 % (mean = 31.6 %), while that found only in the live assemblage was considerably lower (mean = 10.2 %). At nine of the 11 localities the rank abundances of species in the dead and live assemblages were significantly correlated, although in most cases the correlation was not strong. Taphonomic differences among species and localities as well as sample sizes may weaken the correlations, but real change in abundances of certain species may also be involved.
Article
A Veronicellid slug, heretofore unknown in the Gulf Coastal region, appeared in late 1960 in both Mobile and New Orleans. Since then it has spread rapidly throughout much of the area. Studies on the distribution, ecology, and behavior are being made.
Article
Zonitoides arboreus (Say), Opeas pumitum (Pfeiffer), and Lamellaxis gracilis (Hutton) were found commonly in eight greenhouse ranges in New York State. Roses were the only crop grown in those greenhouses. The roses were grown on steam steriliz