Gary Barker

Manaaki Whenua - Landcare Research · Systematics Team

This datasheet on Limax maximus covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Prevention/Control, Further Information.

This datasheet on Marisa cornuarietis covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.

This datasheet on Gonaxis kibweziensis covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.

Conservation status of New Zealand indigenous terrestrial Gastropoda (slugs and snails)

Species threat status for some New Zealand groups of landsnails and slugs

The ambersnails (Succineidae), found nearly worldwide, are considered a very challenging group to classify and identify with even genus-level identifications requiring dissection. In this study, we use mitochondrial and nuclear DNA markers, shell morphometrics, and anatomical dissection to examine fresh material collected from the type localities o...

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...

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.

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...

The terrestrial slug Deroceras invadens has spread across much of the world over the last century. What is there to learn about its origin, colonizations and diversity by comparing barcoding sequences of the mitochondrial gene COI (cytochrome c oxidase subunit I)? Samples from 317 localities covering most of the species' range yielded 87 haplotypes...

Keys to Freshwater Neotropical Molluscs

New Zealand's intensive pastures, comprised almost entirely introduced Lolium L. and Trifolium L. species, are arguably the most productive grazing-lands in the world. However, these areas are vulnerable to destructive invasive pest species. Of these, three of the most damaging pests are weevils (Coleoptera: Curculionidae) that have relatively rece...

An updated taxonomic review of Mollusca from the Neotropical regions is presented in this chapter. Dichotomous identification keys to the lowest justifiable taxonomic level based on the most recent literature are provided. These are coupled with the material preparation methods, defined relevant morphological terms, and current limitations in our k...

DairyNZ’s biosecurity risk analysis project, DBRiEF, has to date evaluated weed and insect hazards to forage production, and disease hazards to animal health. The present report briefly summarises some additional groups of biosecurity hazards to NZ dairy farming, makes some superficial evaluations of the risks they might pose, and gauges if suffici...

Athoracophoridae are succineoidean terrestrial slugs that constitute a distinctive faunal element of the South West Pacific biogeographic region, with representatives in New Guinea, Australia, New Caledonia, Vanuatu and New Zealand. Despite many studies on morphology, taxonomy and phylogenetic relationships since the first species description in 18...

Predator-proof fences have enabled multi-species eradications of mammals from up to 3400 ha on mainland New Zealand. Often, house mice (Mus musculus) are the only mammal remaining in many sanctuaries, and may reach high densities, with unknown biodiversity impacts. This report summarises a 5-year study of mouse abundance and impacts on native biodi...

To test the hypothesis that the inclusion of the forage herbs chicory (Cichorium intybus L.) or plantain (Plantago lanceolata L.) or both in a grass–legume pasture mix improves persistence of sown vegetation and reduces weed and invertebrate pest ingress, a study was undertaken in 31–44 intensively managed pastures in each of five regions in New Ze...

We review the diversity and conservation status of Placostylinae, land snails endemic to the western Pacific. Their narrow-range endemism, large size and associated vulnerability, consumptive exploitation by people, and habitat loss and degradation (inclusive of invasive predators) threaten their survival. There has been considerable attention from...

Where conservation status of island non-marine molluscs is known, snails tend to be one of the most threatened faunal groups. However, published information regarding island gastropod conservation status, diversity and endemism is frequently unavailable despite the importance of this information for the formulation of biodiversity action plans and...

While invasive rats are demonstrably inimical to indigenous vertebrate species, there has not been unequivocal evidence of benefit to invertebrate communities from management of these invasive mammals in New Zealand forest systems. The present study examined the response of land snail communities to intensive management of ship and Norway rats by s...

ABSTRACT Omalonyx geayi Tillier, 1980 was originally described on the basis of specimens from Kaw swamp, French Guiana. This species distinguished from other of Omalonyx d'Orbigny, 1837: (i) by hermaphrodite duct twice as long and sacculate, without radial ducts but a funnel-shaped insertion on the ovariotestis, and (ii) by longitudinal wrinkled fo...

Experiments with artificial diets demonstrated that black field cricket (Teleogryllus commodus (Walker)) and Lepidogryllus sp. were highly responsive to presence of lolines in their diet—quantities of diet consumed declined exponentially with increasing loline concentration. Amount consumed by black field cricket and Lepidogryllus sp. on diet conta...

1.Land-use intensification is increasing dramatically in production systems worldwide. Livestock production is an important component of production land-use and increases in livestock densities have had a wide range of negative consequences. The off-site effects of livestock grazing and trampling on native vegetation adjacent to pastoral land have...

Land-use intensification is a central element in proposed strategies to address global food security. One rationale for accepting the negative consequences of land-use intensification for farmland biodiversity is that it could 'spare' further expansion of agriculture into remaining natural habitats. However, in many regions of the world the only na...

Responses of adult Argentine stem weevil to meadow fescue-perennial ryegrass hybrids, known as Festulolium, infected with the endophyte Epichloë uncinata were investigated and compared with endophyte-free Grasslands Wana cocksfoot and Grasslands Samson perennial ryegrass, and with Samson infected with wild type and AR37 strains of Epichloë festucae...

The potential of loline-containing Epichloë uncinata-infected Festulolium to resist herbivory by black beetle was examined. We tested the hypothesis that concentration of lolines is pivotal to plant protection. A series of non-choice assays were performed, with excised roots and whole plants offered to larvae, artificial diets offered to adult and...

In May 2012 Rotuma Island, the main island of the remote Rotuma Group (Fiji), was surveyed to document the composition of the non-native land snail fauna and to investigate if populations of previously recorded native land snail species persist. From sampling at nine locations, twenty-one land snail species from eleven gastropod families were found...

Abstract: Many wildlife sanctuaries in New Zealand are fenced to exclude exotic mammals. House mice (Mus musculus) remain in many sanctuaries, however, and sometimes become abundant after other mammals are removed. Whether these mice have important impacts on native species is unknown. We estimated changing mouse population densities and measured a...

The South American weevil Listronotus bonariensis (Kuschel) is an important pest of pastures in New Zealand. As a component of management strategies for this pest, the South American parasitoid Microctonus hyperodae Loan (Hymenoptera: Braconidae) was released in northern New Zealand during 1991 as a biological control agent. Over the subsequent 5-6...

A new Alaninema species associated with leaf-veined slugs (Athoracophoridae) in New Zealand is described and illustrated. Alaninema ngata n. sp. is characterised by a very long, cylindrical body, rounded head bearing two circles of cephalic papillae and amphids, shallow stoma with three bifid teeth, muscular, cylindroid pharynx lacking valves, enla...

This document is part of a technical report series on conservation projects funded by the Critical Ecosystem Partnership Fund (CEPF) and the Conservation International Pacific Islands Program (CI-Pacific). The main purpose of this series is to disseminate project findings and successes to a broader audience of conservation professionals in the Paci...

The Department of Conservation Threat Classification ranking of 16 athoracophorid slugs found in Southland Conservancy, inclusive of the southern islands, was assessed. Data were obtained for slugs collected from localities throughout Southland Conservancy during April–May 2012. Information from the observed geographic distributions and older local...

Four pedons on each of four drift sheets in the Lake Wellman area of the Darwin Mountains were sampled for chemical and microbial analyses. The four drifts, Hatherton, Britannia, Danum, and Isca, ranged from early Holocene (10 ka) to mid-Quaternary (c. 900 ka). The soil properties of weathering stage, salt stage, and depths of staining, visible sal...

Habitat loss is one of the greatest threats to species persistence. Gauging the scale of this problem requires quantitative methods that can predict the number of extinctions resulting from habitat loss. For the past three decades, the species-area relationship, an empirical relationship between the number of species present in an area and the size...

Riccardoella limacum (Schrank'i. the slug mite. is recorded from New Zealand for the first time. It has been found on 9 species of terrestrial molluscs, one of which, Athoracophorus bitentaculatus, is a new host record.

Hydrocarbon spills on Antarctic soils occur mainly near settlements where fuel is stored and aircraft and vehicles are refuelled. To investigate those factors that may preclude hexadecane mineralization activity in long-term hydrocarbon-contaminated soils from the Ross Sea Region, samples were collected from Scott Base, the site of former bases (Ca...

In New Zealand, the European invasive slug Deroceras reticulatum is a pest in home gardens, horticulture, pastoral and arable agriculture. At present there are no biological control options available in New Zealand, unlike Europe, where the nematode parasite Phasmarhabditis hermaphrodita is sold in several countries under the trade name Nemaslug®....

Four pedons on each of four drift sheets in the Lake Wellman area of the Darwin Mountains were sampled for chemical and microbial analyses. The four drifts, Hatherton, Britannia, Danum, and Isca, ranged from early Holocene (10 ka) to mid-Quaternary (c. 900 ka). The soil properties of weathering stage, salt stage, and depths of staining, visible sal...

For many taxonomic groups, sparse information on the spatial distribution of biodiversity limits our capacity to answer a variety of theoretical and applied ecological questions. Modelling community-level attributes (α- and β-diversity) over space can help overcome this shortfall in our knowledge, yet individually, predictions of α- or β-diversity...

The Department of Conservation Threat Classification ranking of five endemic slugs found in Northland was assessed. Data were obtained for slugs collected from localities throughout Northland Conservancy. Information from the observed geographic distributions and older locality information were combined to obtain an updated picture of the current d...

A number of factors have combined to diminish ecosystem integrity in New Zealand indigenous lowland forest fragments surrounded by intensively grazed pasture. Livestock grazing, mammalian pests, adventive weeds and altered nutrient input regimes are important drivers compounding the changes in fragment structure and function due to historical defor...

Several invasive European slug species are thriving in New Zealand and have become important pests of many crops. In pasture, they are particularly damaging to white clover during renovation and the problem may be exacerbated by direct drilling. Slug feeding causes both lethal and sublethal damage that reduces clover establishment and thus pasture...

Fiji’s land snail fauna is highly diverse. There are over 230 species of which about 90% are native and 78% are endemic to the archipelago. There are 18 introduced species and four that are of uncertain origin within the Pacific. Information to allow easy identification of these species is lacking, as is related information about the risks involved...

Poor pasture persistence and ingress of weedy species are major concerns for farmers. The seedbank gives an indication of what weedy species may establish in pastures and compete with sown species. It was hypothesised that the above-ground composition reflects the seedbank. The seedbank was sampled and botanical assessments were undertaken during O...

Botanical composition was assessed in spring in 30 paddocks in each of four New Zealand regions: Northland (beef, sheep), Waikato (dairy), Taranaki (dairy) and North Canterbury (beef, sheep, deer). The hypothesis tested was that increasing functional diversity of sown species reduced ingress of unsown species as pastures age. Paddocks selected rang...

The objective of this study was to examine the presence and diversity of Archaea within mineral and ornithogenic soils from 12 locations across the Ross Sea region. Archaea were not abundant but DNA sufficient for producing 16S rRNA gene clone libraries was extracted from 18 of 51 soil samples, from four locations. A total of 1452 clones were analy...

The objective of this study was to examine the presence and diversity of Archaea within mineral and ornithogenic soils from 12 locations across the Ross Sea region. Archaea were not abundant but DNA sufficient for producing 16S rRNA gene clone libraries was extracted from 18 of 51 soil samples, from four locations. A total of 1452 clones were analy...

The Last Glacial Maximum (LGM) severely restricted forest ecosystems on New Zealand's South Island, but the extent of LGM distribution for forest species is still poorly understood. We used mitochondrial DNA phylogeography (COI) and ecological niche modelling (ENM) to identify LGM refugia for the mycophagous beetle Agyrtodes labralis (Leiodidae), a...

Aim  Using New Zealand land snails as a case study, we evaluated recent spatial modelling approaches for the analysis of diversity in species-rich invertebrate groups. Applications and prospects for improved conservation assessment were investigated.Location  New Zealand.Methods  The study used a spatially extensive and taxonomically comprehensive,...

Three new species of Punctoidea from Chilean - Argentine Patagonia are described in the family Charopidae: Lilloiconcha aysensis n. sp., Radiodiscus villarricensis n. sp. and Stephadiscus stuardoi n. sp. The new species of Lilloiconcha and Stephadiscus are known only from type localities in Chile, at Aysen and Concepción, respectively. In addition...

In many agricultural landscapes, significant biodiversity gains can be made by improving the ecological condition of degraded remnants of semi‐natural habitat. Recent emphasis has been on the level of management intervention required to initiate vegetation recovery in small forest remnants, but no comparable emphasis has been placed on benefits for...

The Last Glacial Maximum (LGM) severely restricted forest ecosystems on New Zealand's South Island, but the extent of LGM distribution for forest species is still poorly understood. We used mitochondrial DNA phylogeography (COI) and ecological niche modelling (ENM) to identify LGM refugia for the mycophagous beetle Agyrtodes labralis (Leiodidae), a...

ABSTRACT: In many agricultural landscapes, significant biodiversity gains can be made by improving the ecological condition of degraded remnants of semi‐natural habitat. Recent emphasis has been on the level of management intervention required to initiate vegetation recovery in small forest remnants, but no comparable emphasis has been placed on be...

In the Ross Sea region of Antarctica, ornithogenic soils form on land under Adélie Penguin rookeries. Compared with mineral soils of the Ross Sea region, ornithogenic soils are generally high in microbial biomass, organic carbon, and total nitrogen and phosphorus, with high electrical conductivity and large variations in pH. The objective of this s...

Clavicipitaceous fungi of the genus Neotyphodium occur widely as mutualistic, systemic, seed-borne infections in festucoid grasses. Grass infection by these fungi is associated with the presence of a range of secondary metabolites (SM), several of which have been demonstrated to confer to the plant resistance against herbivorous vertebrates and ins...

This study estimates the relative contributions of environment and farm management strategies in influencing soil faunal assemblages and attempts to identify the species with potential to affect sustainability of intensive grazing management systems in the north-eastern USA. It arises because of the change from confinement feeding of dairy cattle,...

A recently discovered and threatened large land snail, Powelliphanta augusta n. sp. is described from Mt Augustus on the western scarp of the Stockton Plateau, North Westland. On shell characters it is readily distinguishable from all other Powelliphanta, with narrow red spiral lines underlying irregular and variable dark reddish‐brown axial bands,...

Soils of the Ross Sea r