Paul D. Pratt

Paul D. Pratt
United States Department of Agriculture | USDA · Agricultural Research Service (ARS)

Doctor of Philosophy

About

175
Publications
26,562
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2,917
Citations
Additional affiliations
October 1999 - May 2016
United States Department of Agriculture
Position
  • Research Entomologist

Publications

Publications (175)
Article
Full-text available
Nonnative invasive plants (weeds) negatively impact native biodiversity, ecosystem services, agriculture, and the economic interests and health of humans. Since 1902, biological weed control has been employed as a cost-effective and sustainable management option for weeds in the USA. However, biological control is not appropriate for all weeds, nor...
Article
Full-text available
The U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) has been a leader in weed science research covering topics ranging from the development and use of integrated weed management (IWM) tactics to basic mechanistic studies, including biotic resistance of desirable plant communities and herbicide resistance. ARS weed scientists...
Article
The Scotch broom gall mite, Aceria genistae, is an adventive herbivore of Cytisus scoparius (Scotch broom), an invasive non-native shrub in California, USA. Although feeding by these mites clearly induces localised tissue distortion, the effect of A. genistae on overall host vigour and reproduction has not been assessed. Here we compare biomass all...
Article
Ecological niche models of species occurrence have gained interest in biological control programs to improve efficiency, reduce risks, and to inform when and how control agents may be released and/or surveyed. Alligator weed, Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae), is an amphibious aquatic plant native to southern South America...
Article
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Lack of successful biological control of alligatorweed, Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae), by Agasicles hygrophila Selman & Vogt (Coleoptera: Chrysomelidae) in the USA is an emerging problem as A. philoxeroides expands into temperate climates due to poor cold tolerance of the beetles. Sourcing climatically suited biotypes...
Article
Invasive alien species are among the most important threats to biodiversity, with invasive plants ranking among the highest. Classical weed biological control—or biocontrol—reunites exotic plants with hostspecific natural enemies from their native range with the aim of controlling the invasive plant.We reviewed the attention classical weed biocontr...
Article
South American invasive plants in the genus Ludwigia (Onagraceae) degrade many riparian and aquatic ecosystems worldwide. Biological control may aid in the management of these exotic weeds, but data on the host specificity of Ludwigia natural enemies is limited. The biology and host range of Sudauleutes bosqi Hustache (Coleoptera: Curculionidae), a...
Article
Exotic water primroses are aggressive invaders in both aquatic and riparian ecosystems worldwide. Water primrose [Ludwigia hexapetala (Hook. & Arn.) Zardini, Gu & P. H. Raven], floating primrose-willow [Ludwigia peploides (Kunth) P. H. Raven subsp. peploides], floating primrose-willow [Ludwigia peploides (Kunth) P. H. Raven subsp. montevidensis (Sp...
Article
A 6-year time-series study in the Western Everglades region of Florida, United States examined the influence of woody debris from two tree species on invertebrate richness, abundance, and diversity, as well as tree debris mass loss, fragmentation, and residence time. Samples of decomposing fine woody debris and coarse woody debris (CWD) from non-na...
Article
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Many weed biological control programs suffer from large-scale spatial variation in success due to restricted distributions or abundances of agents in temperate climates. For some of the world’s worst aquatic weeds, agents are established but overwintering conditions limit their survival in higher latitudes or elevations. The resulting need is for n...
Article
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Exotic water primroses (Ludwigia spp.) are aggressive invaders in aquatic ecosystems worldwide. To date, management of exotic Ludwigia spp. has been limited to physical and chemical control methods. Biological control provides an alternative approach for the management of invasive Ludwigia spp. but little is known regarding the natural enemies of t...
Article
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Dioscorea bulbifera has invaded, smothered, and disrupted ecological functions of native plant communities in Florida. Vines senesce in late fall, then overwinter as tubers and aerial bulbils which sprout in spring and repeat the growth cycle. A foliage-feeding beetle Lilioceris cheni, introduced from Asia as a biocontrol agent has established thro...
Article
Variability in the effectiveness of biological control programs can be due to a myriad of abiotic and biotic interactions. Here, we explore these interactions in relation to the suboptimal biological control on the invasive water hyacinth, Pontederia (=Eichhornia) crassipes, by two weevils, Neochetina bruchi and N. eichhorniae, in the Sacramento-Sa...
Article
Full-text available
The distribution of genetic diversity in invasive plant populations can have important management implications. Alligator weed ( Alternanthera philoxeroides (Mart.) Griseb.) was introduced into the United States around 1900 and has since spread throughout much of the southern U.S. and California. A successful biological control program was initiate...
Article
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Rhodomyrtus tomentosa is a perennial shrub native to Southeast Asia and is invasive in South Florida and Hawai'i, USA. During surveys of R. tomentosa in Hong Kong from 2013-2018 for potential biological control agents, we collected larvae of the stem borer, Casmara subagronoma. Larvae were shipped in stems to a USDA-ARS quarantine facility where th...
Article
Bagrada bug, Bagrada hilaris Burmeister (Hemiptera: Pentatomidae), is an invasive pest of cole crops in the United States. Two egg parasitoids, Gryon gonikopalense Sharma and Trissolcus hyalinipennis Rajmohana & Narendran (both Hymenoptera: Scelionidae), are being evaluated as possible biological control agents for B. hilaris. Unlike most stink bug...
Article
Archernis humilis (Swinhoe) (Lepidoptera: Crambidae) has previously been recorded only from India, and nothing has been reported about its biology or immatures. It was recently discovered during surveys for biological control agents against Paederia foetida L. (Rubiaceae) or skunk vine, and this represents the first report of the food plant. Archern...
Article
Melaleuca quinquenervia (hereafter melaleuca) was until recently one of the worst ecological invaders in Florida. Introduced for horticulture and levee stabilisation during the early twentieth century, melaleuca spread to cover vast areas of the largest freshwater wetlands ecosystem in North America, The Everglades. From 1997 until 2008, four insec...
Article
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Multiple introductions are hypothesized to facilitate the success of invasive plant species, because they can result in novel genotypes through intraspecific hybridization potentially increasing the ability to adapt to the novel environment. In this study, we address the question of how the demography of an invader with multiple introductions and i...
Article
The host range of the thrips Liothrips ludwigi was investigated using single- and multi-generational no-choice nymphal development and oviposition tests. Development, oviposition, and egg viability were quantified when L. ludwigi were fed three exotic Ludwigia species and seven USA native plant species. Liothrips ludwigi completed development and o...
Article
Non-destructive means for estimating Dioscorea bulbifera biomass will help gauge its management efficacy over time. Herein, we developed allometric equations to estimate total and fractional biomass components, and densities of aerial bulbils and underground tubers of field grown Dioscorea bulbifera in Florida. We selected four naturally infested s...
Article
Schinus terebinthifolia is a dioecious tree native to South America that has become an invasive weed in Florida, southern California, southern Arizona, Texas and Hawaii and has been naturalised in over 20 countries. Biological control is considered a viable long‐term control option for S. terebinthifolia because release from natural enemies appears...
Article
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Perennial pepperweed, Lepidium latifolium L. (Brassicales: Brassicaceae), is an invasive weed that can form dense stands and displace native species. Bagrada hilaris Burmeister (Hemiptera: Pentatomidae) is a serious economic pest of Brassicaceae vegetable crops. Bagrada bug also feeds on L. latifolium and may interact with the plant fungal pathogen...
Article
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Invasive species have many detrimental ecological and socio-economic effects. However, invasive species can also provide novel habitat for native species. The growing rate of biological invasions world-wide presents an urgent dilemma: how can natural resource managers minimize negative effects of invasive species without depleting native taxa that...
Article
This report summarises efforts to establish Diorhabda carinulata (Desbrochers) and D. elongata (Brullé) in California for the control of invasive saltcedars (Tamarix spp.), which degrade riparian ecosystems in the western United States. Over 14,000 D. carinulata individuals were released in California among four locations between 1999 and 2002 but...
Article
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The exotic tree Melaleuca quinquenervia (melaleuca) has invaded and formed monotypic forest stands in ecologically sensitive wetlands of Florida. We hypothesized that natural-enemy impact would influence melaleuca’s litter and seed fall dynamics via chronic attacks, and enhance native species diversity, which will be reflected in leaf litter compos...
Article
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Oxyops vitiosa Pascoe (Coleoptera: Curculionidae) was released in Florida in 1997 as a biological control agent of the invasive tree Melaleuca quinquenervia (Cav.) S.T. Blake. Three years after release, the weevil’s dispersal into three replicated M. quinquenervia stands was monitored to determine if O. vitiosa preferentially selects larger trees d...
Article
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Scotch broom (Cytisus scoparius (L.) Link) is a European shrub that has naturalised in several countries worldwide and is recognised as an invasive weed in much of western North America. The mite Aceria genistae (Nalepa) is a coevolved, gall-inducing herbivore associated with Scotch broom in its native range and has been intentionally introduced as...
Article
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The leaf-mining fly Hydrellia egeriae Rodrigues-Junior (Diptera: Ephydridae) was evaluated under quarantine conditions as a candidate biological control agent of the invasive aquatic weed Egeria densa Planchon (Hydrocharitaceae) in California, U.S.A. The objective of this study was to test the fly’s feeding preference for E. densa as compared to th...
Article
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The intentional introduction of exotic species through classical biological control programs provides unique opportunities to examine the consequences of population movement and ecological processes for the genetic diversity and population structure of introduced species. The weevils Neochetina bruchi and N. eichhorniae (Coleoptera: Curculionidae)...
Article
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The invasive tree Melaleuca quinquenervia (Cavanilles) Blake (Myrtaceae) is widely distributed throughout peninsular Florida, U.S.A. and poses a threat to species diversity in the wetland systems of the Florida Everglades. Biological control research targeting the weed resulted in the introduction of Oxyops vitiosa Pascoe, 1870 to Florida. Approxim...
Article
The successful establishment or failure of a new population is often attributed to propagule pressure, the combination of the number of independent introduction events, and the number of individuals released at each event. The design of optimal release strategies for biological control agents benefits from an understanding of the impact of propagul...
Article
A four year common garden study was initiated using once-cut Melaleuca quinquenervia trees that were subsequently subjected to a full factorial of treatments that included reduced versus unrestricted herbivory from biological control agents, a mechanical treatment (trees were not cut or were cut every 6 m), and an irrigation treatment (trees were i...
Article
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Saltcedars are woody plants in the genus Tamarix L. (Caryophyllales: Tamaricaceae) and are native to Eurasia and Africa. Several species have become invasive in the Americas, Australia and South Africa. In Argentina there are four species of Tamarix distributed in arid, semi-arid and coastal areas of most provinces. The taxonomic isolation of Tamar...
Article
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Multiple introductions of an exotic species can facilitate invasion success by allowing for a wider range of expressed trait values in the adventive range. Schinus terebinthifolius (Brazilian peppertree) is an invasive shrub that was introduced into Florida in two separate introductions and has subsequently hybridized, resulting in three distinct l...
Article
Siamusotima disrupta Solis, n. sp., is a stem-boring musotimine from China. It was discovered in the stems of several Lygodium Sw. species (Lygodiaceae) during exploration for biological control agents of Lygodium microphyllum (Cav.) R. Br., the Old World climbing fern. This is the second report of a stem-boring pyraloid larva with a unique, cup-li...
Article
The invasive water hyacinth (Eichhornia crassipes) severely limits the ecosystem services provided by the Sacramento-San Joaquin River Delta in California, USA. As part of the biological control program in the Delta, two weevils, Neochetina bruchi and N. eichhorniae (Coleoptera: Curculionidae) and a moth, Niphograpta albiguttalis (Lepidoptera: Pyra...
Article
A Chinese biotype of Lilioceris cheni Gressitt and Kimoto (Coleoptera: Chrysomelidae) is being mass reared and released in Florida for biological control of the invasive air potato vine, Dioscorea bulbifera L. (Dioscoreales). Another biotype from Nepal is under investigation for determining whether its release would benefit the ongoing biological c...
Article
An invasive grass, Arundo donax, occupies thousands of hectares of arid riparian habitat along the Rio Grande in Texas and Mexico, and has negative impacts on national security, water resources, and riparian ecosystems. The shoot-tip-galling wasp Tetramesa romana was released in 2009 between Brownsville and Del Rio, Texas, and has dispersed over 80...
Article
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The Asian shrub Rhodomyrtus tomentosa (Aiton) Hasskarl (Myrtaceae) is an invasive weed in Florida and Hawaii, U.S.A. Surveys for natural enemies of this exotic shrub in Hong Kong, China resulted in the development of a laboratory colony and host range testing of Neostauropus alternus (Walker, 1855) as a potential biological control agent of R. tome...
Article
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Surveys for natural enemies of Lygodium microphyllum (Cav.) R. Br. (Lygodiaceae) in Thailand resulted in the collection of Archips machlopis Meyrick (Lepidoptera: Tortricidae). Multiple generations of the tortricid were reared on L. microphyllum in a quarantine laboratory, demonstrating that the plant is a developmental host. Further host specifici...
Article
This EDIS publication is an alternate version of a page published first on the Featured Creatures website. The Featured Creatures collection provides in-depth profiles of insects, nematodes, arachnids and other organisms relevant to Florida. These profiles are intended for the use of interested laypersons with some knowledge of biology as well as a...
Article
Dioscorea bulbifera is a serious invader of various ecosystems in Florida, where plants generated by its two morphotypes climb aggressively and smother supporting vegetation. There is a dearth of published research on its invasive biological attributes including vine growth and biomass production by plants generated from bulbils. Herein, we assesse...
Chapter
This chapter presents case histories of selected invasive insects and plants, and discusses the damage they caused to native species, ecosystems, or biodiversity. The Australian tree Melaleuca quinquenervia is one example owing to its ability to alter ecosystem structure and function. Mist flower, Ageratina riparia is a weed in the northern part of...
Article
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The Asian shrub Rhodomyrtus tomentosa is an invasive weed in Florida and Hawaii, USA. Surveys for natural enemies of this exotic shrub in Hong Kong, China, resulted in the development of a laboratory colony and initial host range testing of Carea varipes Walker as a potential biological control agent of R. tomentosa. Twelve critical test plant spec...
Article
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In its native range the invasive weed, Rhodomyrtus tomentosa is host to a suite of herbivores. One, Strepsicrates sp. (Lepidoptera: Tortricidae), was collected in China in 2014, introduced under quarantine in Florida, USA and tested against related species to determine its host range and suitability for biological control. In no-choice tests, neona...
Article
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Two chemotypes of Melaleuca quinquenervia (Cav.) S. T. Blake (Myrtales: Myrtaceae) saplings were planted in a common garden under 2 water treatments and exposed to either restricted or unrestricted herbivory from 2 insect herbivores. Chemotypes consisted of either a predominately E-nerolidol terpenoid complex or one that consisted primarily of viri...
Article
Neomusotima conspurcatalis Warren (Lepidoptera: Crambidae) was first released in Florida, USA, as a biological control agent of Lygodium microphyllum (Cavanilles) R. Brown (Schizaeales: Lygodiaceae), Old World climbing fern, in 2008. The first egg parasitoid, a Trichogramma sp. (Hymenoptera: Trichogrammatidae), was reared from N. conspurcatalis in...
Article
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Three colonies of Neostromboceros albicomus, a candidate biological control agent of Lygodium microphyllum, were barcoded using the D2 expansion domain, to determine which of two biotypes they represented. The first colony, collected in 2005 & 2007, was used for the initial host range testing. Colonies collected in 2012 and 2014 are currently being...
Article
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Old World climbing fern, Lygodium microphyllum (Cav.) R. Br.; Schizaeles: Lygodiaceae), is among the most problematic invasive weeds in southern Florida, USA, where it smothers and displaces native vegetation. Chemical and mechanical control methods that target aerial fronds may not provide adequate control of L. microphyllum as underground rhizome...
Article
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Rhodomyrtus tomentosa is an invasive weed in Florida and Hawaii, USA. Host range testing indicates that the stem-mining lepidopteran Metharmostis multilineata, collected from Hong Kong, China aggressively feeds and completes development on R. tomentosa as well as New World species in three other genera. The unsuitability of M. multilineata as a bio...
Article
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Formosempria Takeuchi, 1929, is distributed in southeastern Asia from Taiwan and China to Vietnam, Myanmar, and possibly northern India. Three species are included: F. crassicornis Wei & Nie, 2002, F. shanensis Malaise, 1961, and F. varipes Takeuchi, 1929 (= F. annamensis Malaise, 1961, syn. n.; = F. metallica Wei, 2003, syn. n.). Formosempria vari...
Article
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The gall-producing midge Lophodiplosis trifida Gagné (Diptera: Cecidomyiidae) is an established biological control agent of the exotic tree Melaleuca quinquenervia (Cav.) Blake, which invades wetland systems of Florida (USA). Host use patterns within the tree canopy were investigated. Plant height affected within-plant distribution of galls as L. t...
Conference Paper
Background/Question/Methods Old World climbing fern, Lygodium microphyllum (Cav.) R. Br (Polypodiales: Lygodiaceae), an invasive weed, is widespread and expanding its range throughout wetland and mesic habitats in Florida. Lygodium microphyllum degrades critical ecosystem services and habitats of rare and endangered species throughout Florida, es...
Conference Paper
Background/Question/Methods Air potato, Dioscorea bulbifera L., (Liliales: Dioscoreaceae) is an invasive herbaceous vine. It does not produce fertile flowers in the U.S. and instead reproduces via aerial bulbils, vegetative propagules that form in the leaf axils and dehisce as this deciduous plant senesces in the fall. Bulbils and persistent subt...
Article
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The brown Lygodium defoliating moth, Neomusotima conspurcatalis Warren (Lepidoptera: Crambidae), was released beginning in 2008 to control Old World climbing fern, Lygodium microphyllum (Cav.) R. Br (Polypodiales: Lygodiaceae). The moth readily established in Jonathan Dickinson State Park, but at other sites populations remained at low densities or...
Article
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The mite Floracarus perrepae Knihinicki & Boczek (Acariformes: Eriophyidae), a biological control agent of Lygodium microphyllum (Cav.) R. Br (Polypodiales: Lygodiaceae), Old World climbing fern, was released in south Florida from 2008 to 2010 but did not readily establish in the field. The original release sites were resurveyed in 2013 and the mit...
Article
Full-text available
The brown Lygodium defoliating moth, Neomusotima conspurcatalis Warren (Lepidoptera: Crambidae), was released beginning in 2008 to control Old World climbing fern, Lygodium microphyllum (Cav.) R. Br (Polypodiales: Lygodiaceae). The moth readily established in Jonathan Dickinson State Park, but at other sites populations remained at low densities or...