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Dive into the research topics where David B. Wahl is active.

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Featured researches published by David B. Wahl.


Molecular Ecology Resources | 2009

Integration of DNA barcoding into an ongoing inventory of complex tropical biodiversity

Daniel H. Janzen; Winnie Hallwachs; Patrick Blandin; John M. Burns; Jean Marie Cadiou; Isidro A. Chacón; Tanya Dapkey; Andrew R. Deans; Marc E. Epstein; Bernardo Espinoza; John G. Franclemont; William A. Haber; Mehrdad Hajibabaei; Jason P. W. Hall; Paul D. N. Hebert; Ian D. Gauld; Donald J. Harvey; Axel Hausmann; Ian J. Kitching; Don Lafontaine; Jean Fran Çois Landry; Claude Lemaire; Jacqueline Y. Miller; James S. Miller; Lee D. Miller; Scott E. Miller; Jose Montero; Eugene Munroe; Suzanne Rab Green; Sujeevan Ratnasingham

Inventory of the caterpillars, their food plants and parasitoids began in 1978 for todays Area de Conservacion Guanacaste (ACG), in northwestern Costa Rica. This complex mosaic of 120 000 ha of conserved and regenerating dry, cloud and rain forest over 0–2000 m elevation contains at least 10 000 species of non‐leaf‐mining caterpillars used by more than 5000 species of parasitoids. Several hundred thousand specimens of ACG‐reared adult Lepidoptera and parasitoids have been intensively and extensively studied morphologically by many taxonomists, including most of the co‐authors. DNA barcoding — the use of a standardized short mitochondrial DNA sequence to identify specimens and flush out undisclosed species — was added to the taxonomic identification process in 2003. Barcoding has been found to be extremely accurate during the identification of about 100 000 specimens of about 3500 morphologically defined species of adult moths, butterflies, tachinid flies, and parasitoid wasps. Less than 1% of the species have such similar barcodes that a molecularly based taxonomic identification is impossible. No specimen with a full barcode was misidentified when its barcode was compared with the barcode library. Also as expected from early trials, barcoding a series from all morphologically defined species, and correlating the morphological, ecological and barcode traits, has revealed many hundreds of overlooked presumptive species. Many but not all of these cryptic species can now be distinguished by subtle morphological and/or ecological traits previously ascribed to ‘variation’ or thought to be insignificant for species‐level recognition. Adding DNA barcoding to the inventory has substantially improved the quality and depth of the inventory, and greatly multiplied the number of situations requiring further taxonomic work for resolution.


Systematic Entomology | 1998

The cladistics and higher classification of the Pimpliformes (Hymenoptera: Ichneumonidae)

David B. Wahl; Ian D. Gauld

The monophyly of the ichneumonid clade Pimpliformes is established and the phylogenetic relationships of the eight component subfamilies are resolved. The clade (Acaenitinae + (Diacritinae + (Cylloceriinae + (Diplazontinae + Orthocentrinae)))) is the sister‐lineage to the clade (Pimplinae + (Rhyssinae + Poemeniinae)). The Nearctic genus Cressonia Dasch is transferred to the Diacritinae from the Orthocentrinae. Tribes are not recognized in the Acaenitinae as the Coleocentrini (sensu Townes, 1971) is paraphyletic with respect to the Acaenitini. The Cylloceriinae is recognized as comprising three genera, Cylloceria Schiødte, Allomacrus Förster and Sweaterella gen.n. The Orthocentrinae, including the Helictinae of authors, is shown to be monophyletic, but the latter is clearly shown to be paraphyletic if the Orthocentrus genus‐group is excluded. The Pimplinae comprises four monophyletic tribes: the Delomeristini, consisting of Delomerista Förster and Atractogaster Kriechbaumer; the Perithoini trib.n., which includes only Perithous Holmgren (= Hybomischos Baltazar syn.n.); the Pimplini, which includes the Theronia genus‐group as well as the Pimpla genus‐group; and the Ephialtini, which includes the Polysphinctini syn.n., a monophyletic group that previously rendered the restricted Ephialtini paraphyletic. The tribe Delomeristini is the sister‐group to the clade (Ephialtini + (Perithoini + Pimplini)). The subfamily Poemeniinae is recognized as comprising three tribes: the Pseudorhyssini (trib.n.) which includes the single Holarctic genus Pseudorhyssa Merrill; the Rodrigamini (trib.n.) which includes only the Costa Rican genus Rodrigama Gauld; and the Poemeniini. The tribe Pseudorhyssini is the sister‐group to the clade (Rodrigamini + Poemeniini). The phylogenetic inter‐relationships of the genera of Poemeniini are resolved. A new genus from South Africa, Guptella (gen.n.) is described, and Achorocephalus Kriechbaumer is shown to be a synonym of Eugalta Cameron (syn.n.). The evolution of biological traits within the Pimpliformes is discussed with reference to the elucidated phylogeny, and zoogeographic patterns are outlined.


Cladistics | 1992

PHYLOGENY OF THE SUBFAMILIES OF THE FAMILY BRACONIDAE (HYMENOPTERA: ICHNEUMONOIDEA): A REASSESSMENT

R.A. Wharton; Scott R. Shaw; Michael J. Sharkey; David B. Wahl; James B. Woolley; J.B. Whitfield; P.M. Marsh; W. Johnson

Abstract— The recently published phylogeny of Braconidae by Quicke and van Achterberg is reassessed. Character‐state definitions and character polarities are evaluated, and more rigorous methods are suggested. Our results indicate that there are many more parsimonious solutions to their data set, the consensus of which differs substantially from their results. Based on our reassessment, little can be said about the relationships among braconid subfamilies. Consensus trees show the cyclostomes as a largely unresolved basal grade. The two other major lineages which have been proposed, the helconoids and microgastroids, are somewhat better resolved, but not consistently so. Relationships among the helconoids vary considerably depending on the parameters used for parsimony analysis.


Journal of Natural History | 1990

A review of the mature larvae of Diplazontinae, with notes on larvae of Acaenitinae and Orthocentrinae and proposal of two new subfamilies (Insecta: Hymenoptera, Ichneumonidae)

David B. Wahl

Study of larval diplazontine ichneumonids reveals that previous authors misinterpreted basic morphology and that larvae have little value for defining diplazontine genera or elucidating their relationships. Better understanding of diplazontine larvae, combined with new material of Orthocentrus, has led to recognition that Pimplinae, Acaenitinae, Diplazontinae, and Orthocentrinae form a monophyletic group, informally named Pimpliformes. Oxytorus and Tatogaster are not part of this group; Oxytorinae is restricted to Oxytorus and Tatogaster is placed in a new subfamily (Tatogastrinae). In order to establish monophyletic taxa within Pimpliformes, Cylloceria and Alomacrus are placed in a new subfamily (Cylloceriinae) and the remaining former oxytorines are merged with orthocentrines in an expanded Orthocentrinae.


Systematic Entomology | 1993

Cladistics of the genera of Mesochorinae (Hymenoptera: Ichneumonidae)

David B. Wahl

Abstract. A cladistic analysis is presented for the genera of the ichneumonid subfamily Mesochorinae. Nine genera are recognized as valid. Previous work on larval morphology is reviewed and a number of larvae are newly illustrated and discussed. Four new synonyms are proposed: Oncocotta, Piestetron, Plectochorus and Rhaibaspis are all synonymized with Mesochorus, and Stictopisthus is placed back as a synonym of Mesochorus. Four new genera are described: Artherola from South Africa, Chineater from Chile, Thamester from Japan, and Varnado from Morocco. A new key is provided to the mesochorine genera of the world.


Systematic Entomology | 1989

The biology, egg and larvae of Acaenitus dubitator (Panzer) (Hymenoptera, Ichneumonidae: Acaenitinae)

Mark R Shaw; David B. Wahl

Acaenitus dubitator (Panzer) is found to be a koinobiont endoparasitoid of the larva of an endophytic beetle, Cleonis piger (Scopoli) (Curculionidae), in Britain, suggesting a similar mode of development for the ichneumonid subfamily Acaenitinae as a whole. The parasitoid can overwinter in its cocoon in one of two ways. Individuals overwintering as essentially unaltered mature larvae do not become adult the following summer, while those that overwinter as morphologically distinct prepupae are committed to pupate and become adult immediately afterwards. The change from mature larva to prepupa takes place in late summer, soon after the time of cocoon formation, but a proportion of mature larvae lie over in the first year, and perhaps subsequently. This appears to be an adaptation to life in a particularly harsh and uncertain environment. The egg, prepupa, and first, second and final instar larvae are described and figured. Previous interpretations of the cephalic sclerites of final instar acaenitines are revised.


Journal of the Kansas Entomological Society | 2007

A New Species of Collyria Schiødte (Hymenoptera: Ichneumonidae: Collyriinae), a Parasitoid of Cephus Fumipennis (Hymenoptera: Cephidae) in China, and Potential Biological Control Agent for Cephus Cinctus in North America

David B. Wahl; Thomas G. Shanower; Kim A. Hoelmer

Abstract A new species, Collyria catoptron, is described from Gansu Province, China. It is an egg-larval koinobiont parasitoid reared from Cephus fumipennis, a grass-mining sawfly that attacks wheat. Collyria catoptron is currently being evaluated as a possible biological control agent for Cephus cinctus in North America.


Journal of Natural History | 2002

The Eucerotinae: a Gondwanan origin for a cosmopolitan group of Ichneumonidae?

Ian D. Gauld; David B. Wahl

A new genus and species of the formerly monobasic and predominantly amphitropical, ichneumonid subfamily, Eucerotinae, is described from Chile. A phylogenetic analysis of the redefined Eucerotinae is undertaken. Barronia araucaria gen. et sp. n. has a sister-group relationship with Euceros. The southern hemisphere species of the latter genus were found to comprise a monophyletic clade, the sister group to all other Euceros species. Similarly all north temperate Euceros species form a monophyletic clade, the sister group of which occurs in Madagascar. Within the former clade, the North American species form a monophyletic group, the sister species of which is Palaearctic. Several other groups of Palaearctic taxa have a sister-group relationship to this lineage. These results suggest the Eucerotinae had an ancient origin on Gondwanaland in the lower Cretaceous, prior to the separation of the Indo-Madagascar terrane from the Australian-Antarctic-South American tectonic plate. We hypothesize the Palaearctic fauna colonized Eurasia following the impaction of India on to its southern margin, and that the North American fauna is derived from a single circum-polar dispersal from Eurasia. Our results do not support an earlier hypothesis that the Eucerotinae arose as hyperparasitoids of Symphyta. Evidence suggests the group arose as parasitoids of ophioniform ichneumonids attacking lepidopterous larvae feeding on gymnosperms or anemophilous angiosperm trees.


Journal of The New York Entomological Society | 2001

AN ENORMOUS NEST OF VESPULA SQUAMOSA FROM FLORIDA, THE LARGEST SOCIAL WASP NEST REPORTED FROM NORTH AMERICA, WITH NOTES ON COLONY CYCLE AND REPRODUCTION

K. M. Pickett; D. M. Osborne; David B. Wahl; J. W. Wenzel

Abstract A nest of Vespula squamosa (Drury) is described including colony size, biomass, and ecological impact. This is the largest vespid nest described from North America to date.


Proceedings of the Entomological Society of Washington | 2012

Review of Parasitoid Wasps and Flies (Hymenoptera, Diptera) Associated with Limacodidae (Lepidoptera) in North America, with a Key to Genera

Michael W. Gates; John T. Lill; Robert R. Kula; James E. O'Hara; David B. Wahl; David R. Smith; James B. Whitfield; Shannon M. Murphy; Teresa M. Stoepler

Abstract. Hymenopteran and dipteran parasitoids of slug moth caterpillars (Lepidoptera: Limacodidae) from North America are reviewed, and an illustrated key to 23 genera is presented. Limacodid surveys and rearing were conducted during the summer months of 2004–2009 as part of research on the ecology and natural history of Limacodidae in the mid-Atlantic region of the U.S.A. Parasitoid rearing involved a combination of collecting naturally occurring larvae in the field (at least 14 host species) and placing out large numbers of “sentinel” larvae derived from laboratory colonies of three host species. Species in the following families are documented from limacodids in North America as primary or secondary parasitoids (number of genera for each family in parentheses; number of genera included in key but not reared through this research in brackets): Chalcididae ([1]; Hymenoptera: Chalcidoidea), Eulophidae (3; Chalcidoidea), Pteromalidae ([1]; Chalcidoidea), Trichogrammatidae (1; Chalcidoidea), Braconidae (3 [1]; Hymenoptera: Ichneumonoidea), Ichneumonidae (7 [3]; Ichneumonoidea), Ceraphronidae (1; Hymenoptera: Ceraphronoidea), Trigonalidae (2; Hymenoptera: Trigonaloidea), Bombyliidae ([1]; Diptera: Asilioidea), and Tachinidae (3; Oestroidea). We recovered 20 of 28 genera known to attack limacodids in North America. Records discerned through rearing in the mid-Atlantic region are augmented with previously published host-parasitoid relationships for Limacodidae in North America north of Mexico. New records are reported for the following parasitoids (total new records in parentheses): Uramya limacodis (Walker) (1), U. pristis (Townsend) (5), Austrophorocera spp. (6), Ceraphron sp. (1), Alveoplectrus lilli Gates (1), Playplectrus americana (Girault) (10), Pediobius crassicornis (Thomson) (1), Trichogramma (1), Mesochorus discitergus (Say) (1), Hyposoter fugitivus (Say) (1), and Isdromas lycaenae (Howard) (5). The male of Platyplectrus americana (Hymenoptera: Eulophidae) is redescribed, and the female is described for the first time. Incidental and miscellaneous host-parasitoid associations are discussed, and it is concluded that most of these records are likely parasitoids of contaminants accidentally introduced during the limacodid rearing process. Triraphis eupoeyiae (Ashmead), new combination, is transferred from Rogas (Hymenoptera: Braconidae).

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Karen R. Sime

University of California

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James B. Whitfield

Illinois Natural History Survey

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Andrew M.R. Bennett

Agriculture and Agri-Food Canada

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Mark R Shaw

Natural Resources Canada

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Andrew R. Deans

Pennsylvania State University

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Bernardo Espinoza

North Carolina State University

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