Location: Systematic Entomology Laboratory
2024 Annual Report
Objectives
Objective 1: Conduct integrative taxonomic research that incorporates adult, immature, and molecular data to develop new and improve existing classifications of agriculturally important insects, create biosystematic databases, determine host plants, and analyze phylogenetic relationships based on next-generation sequencing, comparative morphological and bioinformatics analyses, and modern illustration methods. [NP304, C1, PS1A; C2, PS2B; C3, PS3A and 3B; C4 PS4A and 4B]
Objective 2: Generate molecular and morphological diagnostic tools that will allow stakeholders and beneficiaries (e.g. Animal and Plant Health Inspection Service, Department of Homeland Security, state departments of agriculture, foreign and domestic biological control laboratories, researchers, and citizens worldwide) to accurately identify and rank agriculturally important insects. [NP304, C1, PS1A; C2, PS2B; C3, PS3A; C4 PS4A and 4B]
Objective 3: Curate and expand through fieldwork and acquisitions the U. S. National Insect Collection to support morphological and molecular research by U.S. scientists and stakeholders worldwide and enhance pest insect diagnostics. [NP304, C3, PS3A; C2, PS2B; C3, PS3A; C4 PS4A and 4B]
Objective 4: Provide expert/authoritative identifications for early detection of potentially invasive or novel insect pests intercepted by APHIS or Homeland Security personnel at U.S. ports, and generate research associated with specimens submitted by ARS researchers for biological control research with U.S. state departments of agriculture and U.S. university scientists. [NP304, C1, PS1A; C2, PS2B; C3, PS3A and 3B; C4 PS4A and 4B]
Approach
Parasitoid and phytophagous wasps (Hymenoptera) are a species-rich and biologically diverse group of insects critical to managing pests of agriculture and natural resources. Of the various types of natural enemies, parasitoid wasps are most frequently used to control pest insects. Phytophagous wasps include plant pests and species used to control weeds. We propose to acquire and analyze morphological and molecular character data (and other biosystematic and natural history data) for beneficial and pest chalcidoid, ichneumonoid, and cynipoid wasps to (1) discover and describe new taxa, as well as discover and report new natural history data; (2) generate phylogenies to estimate evolutionary relationships and dates of divergence for lineages, and predic host range for species; (3) propose new taxonomic concepts based on hypotheses of evolutionary relationships and make corresponding nomenclatural changes; (4) redescribe taxa to reflect changes in how they are defined or report new diagnostic character states; and (5) develop tools for identifying taxa. The aforementioned will be generated through phylogenomic research on Chalcidoidea, Ichneumonoidea, Ceraphronoidea, Platygastroidea and Cynipoidea, resulted in revised classifications and species delimitations. We also propose to (1) increase access to the National Insect Collection through digitizing the Hymenoptera type collection and providing that data online, as well as the Hymenoptera ethanol collection; (2) provide authoritative identifications of hymenopterans for USDA-ARS, USDA-APHIS, and other state and federal researchers and action agencies; and (3) curate selected wasp groups in the National Insect Collection (NIC) at the Smithsonian Institution National Museum of Natural History (NMNH).
Progress Report
Coleoptera research focused on generating beetle genomic DNA extractions. Furthermore, DNA grade beetle tissues were collected to improve the taxonomic scope of each Sub-objective. In addition to the progress made in the molecular laboratory, Agricultural Research Service (ARS) researchers conducted research within a grant funded by the USDA-ARS SCINet Higher Performance Computing. The grant funded a postdoctoral associate for two years to investigate the prevalence of hybridization and introgression in agroecosystems. Both the results and bioinformatic tools developed as part of this grant will improve subsequent studies that address prevention and control of non-native agriculturally important beetle species using genomic data. The first phylogenomic hypothesis and revision at the generic-level classification of Cossoninae (Coleoptera: Curculionidae) was substantially delayed due to reduced access to the collection and molecular laboratory during the pandemic, but progress is being made in taxon selection. A synopsis of Nearctic Baridinae genera is in progress and will be submitted for publication in FY2024. A morphological character study and data matrix is underway for Nearctic baridines; initially focusing on external characters due to constraints. Progress on the West Indian flea beetle genera project includes a compiled and substantially edited chapter providing information for all 59 genera occurring in the West Indies. The database containing all 396 West Indian valid flea beetle species has been edited and original descriptions for all the species are examined. Two only outstanding taxonomic issues that remain to be solved are identified: (1) generic placement of Aphthona lamprocyanea and (2) classification of West Indian Monoplatina. Significant progress was made on revisionary study of North American Longitarsus. The type specimens of all 45 native species were obtained, examined, dissected and imaged with more than 800 high resolution images. A Lucid matrix for native and adventive 54 Longitarsus species is initiated with 28 characters and 69 character states.
An analysis of the evolutionary relationships among the species of Anastrepha, the largest and most economically important fruit fly group in the tropical Americas was completed. Analysis of the evolutionary relationships among all fruit flies (>200 of the 500 genera) and related families is progressing. A previously unknown fruit fly species attacking passion fruit in Brazil was named and described, and the results of a survey of fruit flies in Bangladesh were prepared for publication. Phylogenomic data were used to investigate relationships within Phytomyza, the largest genus of agromyzids, containing numerous polyphagous pest species. Associations between leafminer and host-specific parasitoids were established. Population genomic structure within the invasive polyphagous pests L. trifolii and L. sativae was assessed with phylogenomic population data to explore cryptic species and host-plant associated divergence. These results offer insights on the evolution of host-use patterns and specialization in Liriomyza pest species.
Lepidoptera submitted a novel, phylogenomics-based classification of the Prominent moths (Notodontidae), creating eight new subfamilies and a new tribe with extensive caterpillar images from all recognized suprageneric taxa. We clarified the relationships among subfamilies in the family Gelechiidae by analyzing morphological characters of poorly known species underrepresented in previous cladistic hypotheses. We provided clarity and fixed the identity of a worldwide snout moth (Pyraloidea) genus by designating a Neotype and providing a list of about 200 species that remain misplaced in the genus, and described only the second amber fossil that can fine-tune diversification events and their genesis in evolutionary history. A snout moth species was reported as a new U.S. continental record and snout moth larva was identified for the first feeding on fig in California. A virtual dashboard and set of analytical tools for examining APHIS pest interception lepidopteran data over time was created in collaboration with APHIS. Provided diagnostic tools for their identification at the species level of the lantana leafroller and related species in the Western Hemisphere, a sugarcane borer species reported for the first time from Honduras, and ongoing DNA extraction/sequencing/barcoding of intercepted specimens of select noctuid genera in coordination with APHIS (Colorado). Curated economically important snout moth genera in the adult collection, curated the economically jmportant Euzophera larval collection, and processed, labeled, and curated the Janzen Costa Rican noctuoid collection.
Hymenoptera research focused on hundreds of various species of parasitic wasps associated with: stink bugs that eat major food crops in the US and infest homes; pest flies that eat strawberry, blackberry, and other fruit, as well as beneficial flies that parasitize snails and slugs; herbivorous and wood-boring insects in forests worldwide that feed on trees and kill them; plant-feeding insects in grasslands adjacent to crop fields; invasive spiders in Europe; and fire ants that disturb livestock. Along with clarifying identification, new biological attributes and host records were discovered for wasps important to agriculture and natural resources. Correct identification of biological control agents, as well as an understanding of their biological role in mitigating pestiferous species populations, is essential for making rearing and quarantine decisions in the protection of U.S. agricultural interests worldwide. Lastly, collaborative projects with other scientists in Brazil, Mexico, Thailand, and the U.S. have resulted in the most extensive and complete estimates of evolutionary relationships for Braconidae and several groups within that family.
Accomplishments
1. Re-classification of the flea beetles. Flea beetles are plant feeders that belong to a hyper diverse group of about 9,900 species, many of which are serious pests and feed on crops destroying valuable plants costing the U.S. economy millions of dollars annually. USDA-ARS researchers in Beltsville, Maryland, in collaboration with researchers in Belgium, China, Germany, and Turkey, studied historical beetle collections and conducted field investigations in China. In-depth examination of the beetle specimens resulted in significant changes in flea beetle classification. Five species and one genus new to science were described, illustrated and put into context of current classification. Several beetles described in late 1700 and early 1800's were transferred to appropriate genera, tribes and families. New observations of interactions of flea beetles with their host plants were documented. The resulted flea beetle classification is more inclusive, predictive, logical and user friendly and assures easy access to the information on beetle relationships and other biological traits. Improved classification is an important tool for agricultural scientists, practitioners, biological control researchers and anybody interested in plant feeding beetles.
2. New families and species of moths. Noctuoidea is the largest superfamily of Lepidoptera, with over 50,000 described species, yet the relationships among the 6 currently recognized noctuoid families are poorly resolved. When compiling genomic data for one of these families, the Notodontidae, or Prominent Moths, USDA-ARS scientists in Beltsville, Maryland, discovered that one of its component subfamilies was in fact an entirely distinct lineage outside the family and possibly the sister group to all the remaining noctuoid families. Grass-feeding moth identities in the U.S. after more than a hundred years. A grass-feeding moth described in 1794 from the U.S. Virgin Island of St. Croix was the name applied to a widely distributed U.S. species. A researcher located at the National Museum of Natural History, Smithsonian Institution, Washington, D.C., collaborated with researchers from Switzerland, England, and Germany, to adapt molecular methods to target the barcode gene in hundred-plus-year-old type specimens located in European and American museums, and together with structural characters, fixed the identity of this group of grass-feeding species. Another species described from Bermuda in 1915 is the correct name to be applied to the more widespread North American species. Researchers in other USDA labs will use these revised species, genera and families to increase the accuracy of their work.
3. Research on the evolutionary history of wasps. Research on several braconid wasp phylogenomics studies were completed. The studies included hundreds of braconid species and elucidated evolutionary relationships that were previously unknown or ambiguous. New tribes, genera, and species were proposed to reflect the newly recovered relationships. Mitogenome structure was explored for inferring evolutionary relationships within Braconidae and was found to be a valuable source of data for phylogenetic inference. Scientists in other labs depend on reliable phylogenies for their own research. Without such well resolved and strongly supported phylogenies, it is extremely difficult to reliably predict what parasitoids will be useful in biological control. In addition to braconid phylogenomics, USDA-ARS scientists in Beltsville, Maryland, collaborated to assess the impact of braconid parasitoids in regulating wheat stem sawfly (WSS) populations sampled from cultivated wheat and a variety of wild grasses in crop fields and adjacent seminatural grasslands. They found higher levels of WSS parasitism in certain wild grasses than in wheat; thus, wild grasses are possibly important for supporting populations of WSS parasitoids.
4. Fruit flies and leaf mining fly diagnostics improve identification. The systematics of flies (Diptera), including new host plant data and distribution records for leaf-mining fruit flies in the United States and Canada; descriptions of the larvae of 9 species of fruit flies; and an analysis of sexual dimorphism in a group of fruit flies feeding on sunflowers and relatives were elucidated. The evolutionary relationships within the largest and most economically important group of fruit flies in the American tropics (Anastrepha) resulted in the discovery of new, more reliable diagnostic data. An online identification tool for the more than 350 species of Anastrepha was enhanced. Further sampling and continued NextGen sequencing produced additional data for a phylogenetic analysis of the evolutionary relationships of the entire family of fruit flies, which include numerous pest species. Additional names, distribution and host plant data for fruit flies were compiled to be added to the comprehensive database available via USDA Compendium of Fruit Fly Host Information; this information is critical to regulatory agencies to prevent the spread of pest species into the U.S. Researchers will use these revised species, genera and families to increase the accuracy of their work.
Review Publications
Solis, M.A., Leger, T., Neumann, C. 2023. First pyraloid (Insecta, Lepidoptera) caterpillar from Dominican amber. Nota Lepidopterologia. 46:145-154. https://doi.org/10.3897/nl.46.108745.
Solis, M.A., Mally, R., Hayden, J.E., Nuss, M. 2023. Revision of the type species of Syllepte Hübner and other spilomeline genera recently synonymized (Lepidoptera: Crambidae). Zootaxa. 5389(3)343-361. https://doi.org/10.11646/zootaxa.5389.3.3.
Metz, M. 2024. Dates of publication per the ICZN for issues of the proceedings of the entomological society of Washington archived on bioOne. Proceedings of the Entomological Society of Washington. 125 (3):320-325. https://doi.org/10.4289/0013-8797.125.3.320.
Lanzafame, T., Metz, M., Antwi, J. 2024. Lesser maple leaf blotch miner, phyllonorycter lucidicostella (Clemens) (Lepidoptera Gracillariidae), confirmed in Virginia. Proceedings of the Entomological Society of Washington. 125(3):426-427. https://doi.org/10.4289/0013-8797.125.3.426.
Solis, M.A., Cock, M.W., Janzen, D., Hallwachs, W. 2024. New World Orphanostigma Guenée including a new species from Costa Rica (Lepidoptera Crambidae Spilomelinae). Zootaxa. 5471(3):383-390. https://doi.org/10.11646/zootaxa.5471.3.8.