Location: Systematic Entomology Laboratory
2022 Annual Report
Objectives
Objective 1: Develop new and improve existing classifications of agriculturally important beetles based on next-generation sequencing (e.g., in cooperation with the Ag100Pests Initiative), comparative morphological and bioinformatics analyses, and modern illustration methods. [NP304, C1, PS1A; C2, PS2B; C3, PS3A and 3B; C4 PS4A and 4B – Appendix 1]
Sub-objective 1.A: Phylogenomic estimate of the leaf beetle (Coleoptera: Chrysomelidae) phylogeny with particular emphasis on flea beetles (Chrysomelidae: Galerucinae: Alticini).
Sub-objective 1.B: Infer the first phylogenomic hypothesis and revise the generic-level classification of Cossoninae (Coleoptera: Curculionidae).
Objective 2: Generate morphological and molecular 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 beetles. [NP304, C1, PS1A; C2, PS2B; C3, PS3A; C4 PS4A and 4B]
Sub-objective 2.A: Interactive guide for flea beetle genera of the West Indies.
Sub-objective 2.B: Generic reassessment and Illustrated key to Nearctic Baridinae.
Objective 3: Curate and expand the U. S. National Beetle 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]
Sub-objective 3.A: Curation of the National Leaf Beetle collection.
Sub-objective 3.B: Curation of the National Curculionoidea Collection.
Objective 4: Provide identifications of beetles, including plant-feeders, wood-borers, and others of agricultural, economic and environmental importance. [NP304, C3, PS3A; C2, PS2B; C3, PS3A; C4 PS4A and 4B]
Approach
To achieve objectives outlined in the plan, beetle taxon sampling will be centered around testing each hypothesis, while making every attempt to include multiple representatives of each rank to recognize the potential phylogenetic effects of contamination and systematic biases. For Chrysomelidae, the largest and most geographically inclusive taxon sample of about 600 genera across all major groups will be assembled. Cossonines from all over the world, including from recent expeditions have been accumulated. For both beetle groups field expeditions to collect missing taxa are planned to Africa, Australia, Central and South America. Variety of techniques and methods will be used for estimating phylogenies: Qiagen DNeasy Blood and Tissue Kit for DNA extraction; PHYLUCE pipeline to increase the success of hybrid capture experiments; PartitionFinder v2 - to determine the best-fit models of evolution and partition scheme according to the Bayesian Information Criterion, ASTRAL-III v5.1.1 with the set of ML gene trees, will be used to estimate the species phylogenies and, finally, as each of our hypotheses is largely taxonomic in scope; we will use our molecular data and estimated gene and species phylogenies to statistically test proposed molecular hypotheses against all other phylogenetic hypotheses that have been published for each focal lineage using the gene genealogical interrogation test (GGI). Taxon sampling for revisionary objectives of the plan are based on the taxonomic literature, museum records, available databases, and include specimens housed at the National Beetle collection (USNM), museum holdings around the world and include field work to fill the gaps in overall sample. Type species of each genus will be the focus to determine “generic level” morphological characters. Specimens will be examined for morphological features using light microscopy, scanning electron microscopy, and phase contrast compound microscopy. Finally, morphological data will be used to produce identification tools such as guides, keys, comparative descriptions, and diagnoses. Computerized, interactive identification tools on beetle taxa, developed with the assistance of computer programs such as DELTA and LucID, will be created and disseminated via the Internet. National Beetle collection is maintained and enhanced in accordance with the USNM Collections Management Procedures through field work, donated collections and specimens kept from identifications, which are mounted, labelled or otherwise processed, accessioned, databased, and incorporated into the main collection, both “dry” and DNA grade. Identification of beetles submitted by APHIS-PPQ, research and regulatory organizations in the U.S. and abroad is performed using variety of tools available at the USNM, main of which is the National Beetle collection. Identifications are reported using the SEL Identification System (SELIS) and APHIS-PPQ ARM on a daily basis as specimens are intercepted and identified. The information is tracked for decades, which provides critical data for taxonomic research programs in areas such as predictive distribution models for invasive species.
Progress Report
This is the final report for 8042-22000-312-000D. For further information (post-PDRAM approval date) see report for project 8042-22000-317-000D.
Progress was made in objectives all of which fall under National Program 304, Component 1, Systematics and Identification, Problem Statement 1A, Insects and Mites.
In regard to objective 1, ARS researchers in Washington DC (Smithsonian Institution) continued to complete beetle genomic DNA extractions now that the laboratory is open without restrictions. Furthermore, DNA grade beetle tissues were collected and solicitated to improve the taxonomic scope of each sub-objective. In addition to the progress made in the molecular laboratory, ARS researchers were successful in obtaining a grant funded by the USDA-ARS SCINet Higher Performance Computing. The grant will fund 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 Objective 1 subsequent studies that are address prevention and control of non-native agriculturally important beetle species using genomic data.
Significant progress was made in Objective 2. West Indian flea beetle were substantially revised. New genera and species from the subtribe Oedionychina in the West Indies were described, illustrated, and overall revised. A Lucid file for West Indian flea beetles was significantly improved based on the specimens housed at the collection of the West Indian Coleoptera Project (Bozeman, Montana). Images of 15 West Indian flea beetle species were generated and edited for publication quality.
A synopsis of Nearctic genera of Cassoninae is in progress. A morphological character study and data matrix is underway for both cossonines and Nearctic baridines; initially focusing on external characters due to constraints. A phylogenetic assessment of the silky cane weevil, Metamasius hemipterus species complex was submitted based on genomic data and work is ongoing on the first assembly of the genome of Metamasius hemipterus.
Objective 3 did not see much progress as museum was substantially closed, which prohibited major curation activity. However, DNA grade collection of leaf beetles grew by about 500 records. About 3000 leaf beetle specimens collected over the years in Europe and Asia were mounted, labelled and partially sorted to genera and species.
For Objective 4, which falls under National Program 304; Component 3, Insects and Mites; Subcomponent 3B, Natural Ecosystems; Problem Statement 3B1, Early detection and prevention of both invasive and native insect and mite pests. ARS researchers in Beltsville, Maryland (Smithsonian Institution), completed identifications of beetles, including those intercepted at all ports-of-entry into the U.S., and those submitted to the laboratory by universities and agricultural extension agencies, and entered the data in the Systematic Entomology Laboratory Identification System. Large numbers of beetle identifications have been made. In the period from May, 25 2021 to May 25, 2022, 1330 submitted lots were identified, including thousands “urgent”, “prompt”, and “rush” submittals for USDA-APHIS-PPQ of specimens intercepted on perishable commodities at the US. ports of entry. “Urgent” identifications (those requiring same day turn-around of specimens intercepted on perishable commodities at ports of entry) have been processed daily as submitted. In addition, ARS researchers submitted a USDA-ARS Innovation Grant to develop an artificial intelligence tool to identify non-native agriculturally important leaf beetles. Specifically, the grant addresses the need for such a tool by focusing on the leaf beetle genus Epitrix, which contains quarantine species that threaten many U.S. agricultural commodities such as potatoes, tomatoes, bell peppers, and eggplants.
Accomplishments
1. Understanding “Masquerade” mechanism of Ppest flea beetles. Flea beetles are plant feeders that belong to a highly diverse group of about 9,900 species, many of which are serious pests and feed on crops and destroy valuable plants and cost millions of dollars annually. Most flea beetles live, feed, and procreate on the upper leaf surface of their host plants, thus making them vulnerable to numerous predators, including birds, ants, and spiders. To avoid these predators, beetles evolved masquerade mimicry - a close resemblance to innocuous, unprofitable decoy objects of their own manufacture, i.e. their own feeding damage. ARS researchers in Washington, DC in collaboration with biologists and statisticians at the University of Santiago de Compostela (Spain) analyzed evolutionary drivers of beetle masquerade. Study of bipartite networks of feeding interactions (beetle species and their host plants of French fauna) revealed that the evolutionary origin of flea beetles masquerading can be partially explained by two hypotheses: (1) the type of leaf tissue is the primary determinant of the color and size of beetle species feeding on them and (2) morphological characteristics of the beetle explain the damage pattern, because beetle species evolve ways to produce feeding damage that matches its own characteristics. Understanding evolutionary strategies used by beetle pests to avoid predation helps to find effective measures to control them.
2. Cossoninae classification. As part of ongoing work on the subfamily Cossoninae, a group that has not been systematically studied since the mid-1800s, a new species was discovered and described that represents a significant range extension for the genus Halorhynchus. This discovery sheds light into the extraordinary ability of cossonine weevils to disperse over vast transoceanic distances and suggests possible higher-level synonymy in the subfamily.
Review Publications
De Oliveria, D., Linzmeier, A.M., Konstantinov, A.S. 2021. Discovery of the first leaf litter inhabiting flea beetles in Brazil (Coleoptera: Chrysomelidae: Galerucinae) with description of two new genera and three new species. Zootaxa. 5068(1):99-114. https://doi.org/10.11646/zootaxa.5068.1.4.
Kaminski, M., Smith, A., Kanda, K., Iwan, D., Kergoat, G. 2021. Old origin for an European-African amphitropical disjunction pattern? New insights from a case study on wingless darkling beetles (Coleoptera: Tenebrionidae: Dendarini). Journal of Biogeography. 49:1-12. https://doi.org/10.1111/jbi.14288.
Weber, D.C., Konstantinov, A.S., Khrimian, A., Bier, A.D., Lubenow, L., Knodel, J., Haber, A.I., Wallingford, A.K., Mason, J., Kuhar, T. 2022. Trapping of crucifer flea beetles (Phyllotreta spp.)(Coleoptera: chrysomelidae) with pheromones and plant kairomones. Journal of Economic Entomology. 115:1-9. https://doi.org/10.1093/jee/toac042.
Folgar-Camean, Y., Gomez-Rodriguez, C., Konstantinov, A.S., Baselga, A. 2021. Hiding among holes: mechanisms underlying the evolution of masquerade in flea beetles (Chrysomelidae). Journal of Animal Ecology. 47(2):137-145. https://doi.org/10.1111/een.13096.
Damaska, A., Konstantinov, A.S., Fikacek, M. 2022. Multiple origins of moss-inhabiting flea beetles (Coleoptera: Chrysomelidae): molecular phylogeny, overview of genera and a new genus from Africa. ZooKeys. 1-30. https://doi.org/10.1093/zoolinnean/zlab112.
Chamorro, M.L., Steiner Jr., W.E., Andriamasimanana, R. 2022. A new species of the Australian Halorhynchus from Madagascar (Coleoptera, Curculionidae, Cossoninae, Onycholipini) informs cossonine classification. ZooKeys. 1100:103-116. https://doi.org/10.3897/zookeys.1100.75987.
