Location: Systematic Entomology Laboratory2013 Annual Report
1a. Objectives (from AD-416):
ARS is interested in performing research to increase and enhance understanding of the systematics of flies (Diptera) important to agriculture and the environment, especially fruit flies, leaf-mining flies, tachinid flies, soldier flies, and wheat pests and their parasitoids. We will develop new identification tools (descriptions, diagnoses, molecular markers, illustrations, keys and computer identification systems), determine the correct names of species and higher taxa, and elucidate the relationships (phylogeny) and classification of select groups of these flies, which include invasive crop pests, parasitoids of plant pests, and potential biological control agents for weeds. The objectives of our project are: 1) Investigate the taxonomy and natural history of Central American and other New World fruit flies; analyze species concepts, develop diagnoses, descriptions, illustrations and identification keys, determine host plants, and analyze phylogenetic relationships; 2) Conduct molecular analysis of pest leaf-mining, galling, and fruit flies, and their parasitoids, including sequencing of DNA of previously unstudied species, development of diagnostic tools, and analysis of phylogenetic relationships; 3) Investigate taxonomy of New World tachinid flies and soldier flies; analyze species concepts, develop diagnoses, descriptions, illustrations and identification keys, and analyze phylogenetic relationships; 4) Provide scientific identifications of plant-feeding and other agriculturally important flies, and 5) Investigate and compile molecular characters for pests and beneficial insects within wheat and grassland habitats to document host patterns and discover possible cryptic species and host races.
1b. Approach (from AD-416):
ARS will undertake research to generate morphological and molecular characters (DNA sequences) that will be used to test species concepts and hypotheses of relationship among agriculturally important flies, wheat pests, and parasitoid wasps that attack them. These data also will be used to develop new diagnostic tools (descriptions, illustrations, keys) to permit more rapid and accurate identification of these flies, wasps, and wheat pests. Databases containing scientific names, distributions, taxonomic literature, and host plant and specimen data pertaining to fruit flies will be expanded and disseminated to the user community. These and other taxonomic tools will be made accessible to the public via publications, the internet, and other electronic media. Timely and accurate identifications of flies will be provided, including those intercepted at ports-of-entry by APHIS-PPQ or submitted by a wide range of scientists and regulatory agencies, and portions of the National Collection in the National Museum of Natural History, a vital tool for research and identification, will be maintained and expanded.
3. Progress Report:
Taxonomy and natural history of Central American and other New World fruit flies. Progress on the taxonomy of Anastrepha, the largest and most economically important group of fruit flies in the American tropics, included description of 13 new species, discovery of additional new species, further development of an electronic identification tool for the more than 250 species of this group, and collection of samples for DNA analysis. Sequences of DNA (2 genes) were obtained for 70 other species of fruit flies for use in analysis of their relationships and to discover new molecular characters for species discrimination. Study of Xanthaciura, which includes species potentially useful as biological control agents of weeds, was largely completed, in addition to description of four new species of another group (Trupanea) which breed in flowers of the sunflower family (Asteraceae). Data from recent publications were added to a host plant database for fruit flies. This information is critical to APHIS-PPQ and other regulatory agencies to prevent the spread of pest species into the U.S. Molecular analysis of pest leaf-mining, galling, fruit flies, and their parasitoids. Primers necessary for DNA sequencing have been designed for both mitochondrial and nuclear genes in a variety of plant-feeding groups of flies and their associated parasitoids. Specifically, these specialized primers have been designed for leafmining flies (Liriomyza, Phytomyza) that are pests of fruit and vegetables, fruit flies (Blepharoneura) that breed in pumpkins and relatives (Cucurbitaceae), and for the braconid wasp parasitoids attacking these groups. DNA has been extracted and sequenced from more than 1200 individual specimens during the period from October 1, 2012 to June 28, 2013. Two manuscripts reporting results from this work are currently being prepared. Data collection is continuing on these groups in order to better understand species limits, ecological interactions, and host ranges of the plant pests and their parasitoids. This information is critical to APHIS-PPQ and other regulatory agencies to prevent the spread of pest species into the U.S. Taxonomy of New World tachinid flies and soldier flies. A key to the species of Belvosia from America north of Mexico has been largely completed, and male genitalia illustrations, critical for identification of the species, are nearly complete for this portion of the project. New material of Belvosia received from collaborator Dan Janzen has been added to the research collection, sorted to morphospecies, and DNA barcoded. The specimens assembled of the soldier fly genus Berismyia have been reviewed and genitalia illustrations are in the process of being completed. The research paper on how to identify the species, and describing new species, is in preparation. Scientific identification of agriculturally important flies. In the period from October 1, 2012 to June 7, 2013, 334 submittals (1,306 specimens) were identified, including 174 "urgent" submittals for USDA-APHIS-PPQ of specimens intercepted on perishable commodities at ports-of-entry.