Research Project: Sustainable Management Strategies for Stored-Product Insects

Location: Stored Product Insect and Engineering Research

2020 Annual Report

Objectives
Objective 1: Identify and describe the functional genomics for physiological systems important to pest management (e.g., the digestive and sensory systems), for key stored product insects (e.g., lesser grain borer, red flour beetle). Sub-Objective 1.A. Sequence the genome of some key stored product pests. Sub-Objective 1.B. Conduct functional genomic studies of stored product pests to identify target genes for bio-rational controls. Sub-Objective 1.C. Evaluation of insect responses to insecticides and mechanisms of recovery and resistance. Objective 2: Develop and improve monitoring technologies, control tactics, and integrated pest management systems for stored product insects (e.g., cigarette beetle, lesser grain borer, red flour beetle, and warehouse beetle). Sub-Objective 2.A. Improve the management of outside sources of stored product insect infestation. Sub-Objective 2.B. Improve protection of bulk stored grain from damage by stored product insects through reduced risk approaches. Sub-Objective 2.C. Improve the effectiveness of reduced risk aerosol insecticides. Sub-Objective 2.D. Improve use of pheromones in integrated pest management programs.

Approach
Our research focus is the management of key pests of stored raw grains and processed grain products. Insect pests cause significant economic loss through direct feeding damage and product contamination throughout food distribution channels. Integrated pest management (IPM) approaches employing a combination of strategies are needed to protect domestic and international food supplies. Our research objectives target important data gaps in IPM programs, with an emphasis on reduced risk products and sustainable strategies that can be integrated to reduce pest infestation issues. We will conduct genome sequencing for several important stored product insect species and use functional genomics to identify targets for new biologically-based insecticides and evaluate insect response to insecticides. We will improve the management of outside sources of insect infestation through an evaluation of population structure and how insects exploit outside food accumulations. For bulk grain protection, we will focus on reduced risk insecticides and aeration to reduce the need to fumigate commodity. Aerosol insecticide usage inside structures is increasing as a structural fumigation alternative, so our research will focus on how applications can be improved. Finally, we will evaluate how pheromone use in monitoring and mating disruption can be improved through a better understanding of insect behavior. Successful completion of this work will result in new methodologies that will improve the quality of stored products, reduce economic loss, and contribute to the improved security of our food supply.

Progress Report
Progress was made under Objective 1, towards the development of comparative genomics analyses that will enable us to identify genes that allow stored products to exploit different grains and processed commodities. A large comparative genomics analysis of over 50 insect genomes led to the identification of rapidly evolving gene families in various taxonomic lineages, and the identification of genes important for exploiting novel ecological niches and food sources. In addition, an in-depth analysis of 1,000 beetle transcriptomes led to the identification of digestive genes that are important for exploiting various food sources, such as wood and plant materials. Interestingly, genes that code for enzymes that degrade plant tissues were detected in insect family Bostrichidae, which includes many stored product insects. The presence of these gene families in the Bostrichids suggests that some stored product insects may have the ability to exploit alternate food resources other than grain. This finding is consistent with previous research that showed that lesser grain borers can exploit alternative food sources in the landscape and respond to volatiles emitted from native plants. The comparative genomics methods and genome resources being developed for this project will enable us to identify genes responsible for these capabilities. Major progress was also made towards the development of genomic resources for stored product insects. Methods were developed for extracting DNA and making long-read sequencing libraries from small amounts of tissue to generate very high quality genome assemblies of stored product insects. This overcomes a major bottleneck in our ability to sequence insect genomes and has led to substantial improvements in our insect genome assemblies for Indianmeal moth, khapra beetle, confused flour beetle, cigarette beetle, drugstore beetle, sawtooth grain beetle, merchant grain beetle, and larger grain borer, which are awaiting annotations. We also finalized the annotation of lesser grain borer genome and performed a detailed curation of sensory-related and digestive genes. Genetic markers for strong phosphine resistance in lesser grain borers were also identified, which will allow researchers to quickly determine whether a population is resistant. In addition, we have added several new insect species to our genome sequencing efforts including Angomouis grain moth, hairy fungus beetle, larger cabinet beetle, and several other species of flour beetle. Complete reference genomes were also obtained for two cricket species that will be genetically improved for food applications. This research will help facilitate the utilization of insects as alternate sources of protein for human and animal feed which is important for our ability to feed a growing world population. For Objective 2, researchers at Manhattan, Kansas, determined that box traps with lids exclude dermestid larvae, while capture rates increased when the lid was left off. In addition, the positioning of this trap was also optimized. Deploying the wall trap at ground level enhanced trapping rate of dermestids, including khapra beetle larvae and adults. In addition, relationships between trap location and season on insect captures were evaluated using long-term monitoring datasets, and significant factors associated with temporal and spatial patterns of insect activity were identified. This will help with determining trap density and placement in monitoring programs. Impacts of mating disruption programs on female behavior and effects of delay in mating on fecundity were determined which could help improve ability to effectively suppress stored product pest population growth. Bioassay methods were developed and refined to evaluate effects of high pheromone concentrations on insect behavior, and initial tests were conducted. Furthermore, the ability of red flour beetle to develop on different types of flours was evaluated, and it was shown that there was considerable variability in susceptibility of wheat alternative flours that are becoming more widely used because of gluten sensitivity. More detailed analysis of development on different varieties of sorghum were also conducted. Sorghum is receiving increased attention as a food crop in the United States, and we have documented that red flour beetle and khapra beetle larvae can grow and develop on milled sorghum fractions and that the lesser grain borer can develop on several commercial varieties. A new grain protectant was evaluated on three different commodities, wheat, maize, and rice. Reductions in movement and ability to feed and colonize grain were immediate after treatment and effects on insect movement were still observed after the grain had been stored for 6-9 months. Impacts on insect movement or ability to feed were no longer observed after the grain had been stored for 12 months. In addition, packaging materials with incorporated insect growth regulator methoprene were tested for their ability to prevent infestations of dermestid beetles. Khapra beetle and larger cabinet beetle larvae exposed on the exterior or interior of the packaging did not develop to the adult stage and less than 2% of all packaging types were invaded by the larvae. A new reduced risk insecticide containing deltamethrin, piperonyl butoxide, and methoprene was also tested and determined to be effective for residual control of lesser grain borer and red flour beetle on several different commodities. This product is now registered with the Environmental Protection Agency and is on the market. We also studied the effectiveness of cold temperatures in controlling stored product insects. Some species are susceptible to cold temperatures and storing grain in cooler environments will reduce damage and infestations; however, there is substantial variation in cold susceptibility among species and life stages. We also showed that cold tolerance can be selected for in warehouse beetles and that other species can acclimate to cold temperatures, leading to new recommendations about how to effectively use cold treatments to manage stored product insects.

Accomplishments
1. Identification of genes for the utilization of novel food sources in insects. ARS scientists at Manhattan, Kansas, in conjunction with researchers from University of Memphis, Indiana University, and several other research institutions performed a large scale analyses of over 50 insect genomes and 1000 beetle transcriptomes that led to the discovery of rapidly-evolving gene families that allow insects to adopt to new food sources. These gene families include those involved in the ability to perceive and respond to volatiles from food resources as well as those involved in the ability to digest complex carbohydrates present in plant cell walls and starchy foods, such as grain. Interestingly, many of these genes were introduced into insects via horizontal gene transfers from fungi/bacteria and were likely key factors in the diversification of beetles during the Jurassic period that resulted in nearly half of all living beetle species. The introduction of these gene families led to the evolution of diverse feeding habits, such as leaf mining, stem and wood boring, and eventually, the ability to feed on stored products. In tandem with these studies, the genomes of ten species of stored product insects were constructed to chromosome scale and will be key to understanding factors that allow these insects to colonize different types of stored products and will ultimately lead to tactics that can reduce and prevent infestations. The ability to make long-read sequencing libraries from small amounts of insect tissue has greatly expanded the number of stored product insect genomes that we have been able to sequence in the past year and will lead to further insights into genetic adaptations that have allowed diverse lineages of stored product insects to exploit stored commodities.

2. New reduced-risk methods for managing stored product insects in processed food and stored grain. The demand for consumer food products that are free of pesticide residues is increasing and there is a strong need to develop environmentally safe methods for controlling insect populations in food products. ARS researchers at Manhattan, Kansas, studied the efficacy of cold treatments and alternative, environmentally safe fumigants to control stored product insects. Cold temperatures can be used to reduce colonization of stored commodities by insects; however, some species can acclimate to cold, which can reduce the efficacy of these treatments. When confused flour beetle and sawtooth grain beetle were exposed to cool temperatures for seven days, cold tolerance significantly increased in adults and to a lesser extent in larvae. In addition, cold tolerance quickly emerged in laboratory populations of warehouse beetle after short-term exposures to cold temperatures and this trait was highly heritable, suggesting that it could be passed on to offspring and that the prevalence of this trait could increase in a population over time. These findings suggest that managers should ensure that cold treatments are timed appropriately before temperatures cool in the fall months and that they are performed for a sufficient duration of time in order to avoid adaptation to such cold treatments in the field. The efficacy of the fumigant methyl benzoate against stored product insects was also tested. This fumigant has been designated a food safe compound by the Food and Drug Administration. High mortalities were observed in red flour beetle and lesser grain borer, but not maize weevil or warehouse beetle. Despite these mixed results, methyl benzoate could be an alternative product for controlling phosphine-resistant strains of lesser grain borer and red flour beetle, which are becoming more prevalent throughout the world. Overall, this research led to the identification of alternatives to pesticides and strategies to optimize their efficacy in the field.

3. Identification of factors that influence aggregation of stored product insects. Stored product insects often aggregate together in grain masses and processed commodities, which leads to increases in population; however, the factors influencing this behavior are not known for many species. Interestingly, lesser grain borers were more attracted to grain that had been previously fed on by other lesser grain borers. In addition, male beetles are known to release aggregation pheromones that can attract females; however, male beetles moved further distances and engaged in behaviors more consistent with active search strategies in the presence of females. This finding suggests that the males are actively trying to locate females in grain masses and also indicates that females might also produce a previously unidentified pheromone that help bring males closer. The identification of this pheromone could be used to improve the efficacy of trapping and monitoring programs. Likewise, khapra beetles, which are invasive quarantine insects in the United States, often aggregate in groups and compounds present on the exoskeleton may influence this behavior. Extracts of cuticular compounds contained high concentrations of oleic acid. In behavioral assays, low doses of this compound were somewhat attractive to khapra beetles, but were strongly repellent at higher doses, suggesting that this compound could be used as a repellent in pest management programs. These results provide new opportunities to identify attractants that can be used in monitoring programs that can increase trap captures and provide more accurate estimates of population levels. In addition, the identification of repellents can be used to help direct insects away from stored commodities and reduce colonization.

Review Publications
Morrison III, W.R., Grosidier, R., Arthur, F.H., Myers, S., Domingue, M. 2019. Attraction, arrestment, and preference by immature Trogoderma variable and Trogoderma granarium to food and pheromonal stimuli. Journal of Pest Science. 93:135-147. https://doi.org/10.1007/s10340-019-01171-z.
Thomas, G.C., Dohmen, E., Hughes, D.T., Murali, S.C., Poelchau, M.F., Glastad, K., Anstead, C.A., Ayoub, N.A., Batterham, P., Bellair, M., Childers, C., Duan, J.J., Gundersen, D.E., Handler, A.M., Hunter, W.B., Scully, E.D., Hackett, K.J., et all. 2020. Gene content evolution in the arthropods. Genome Biology. 21:15. https://doi.org/10.1186/s13059-019-1925-7.
Athanassiou, C.G., Arthur, F.H., Kavallieratos, N.G., Hartzer, K.L. 2019. To acclimate or not to acclimate? Simultaneous positive and negative effects of acclimation on susceptibility of Tribolium confusum (Coleoptera: Tenebrionidae) and Oryzaephilus surinamensis (Coleoptera: Silvanidae) to low temperatures. Journal of Economic Entomology. 112(5):2441-2449. https://doi.org/10.1093/jee/toz136.
McKenna, D.D., Shin, S., Ahrens, D., Balke, M., Beza-Beza, C., Clarke, D.J., Donath, A., Escalona, H.E., Friedrich, F., Letsch, H., Lui, S., Maddison, D., Mayer, C., Misof, B., Murin, P.J., Niehuis, O., Peters, R., Podsiadlowski, L., Pohl, H., Scully, E.D., Yan, E.V., Zhou, X., Slipinski, A., Beutel, R.G. 2019. The evolution and genomic basis of beetle diversity. Proceedings of the National Academy of Sciences. 116(49):24729-24737. https://doi.org/10.1073/pnas.1909655116.
Morrison III, W.R., Lanba, A., Hall, B., Bruce, A.I. 2020. Novel implementation of laser ablation tomography as an alternative technique to assess grain quality and internal insect development in stored products. Journal of Stored Products Research. 86:101552. https://doi.org/10.1016/j.jspr.2019.101552.
Athanassiou, C., Phillips, T., Arthur, F.H., Aikens, M.J., Agrafioti, P., Hartzer, K.L. 2020. Efficacy of phosphine to different life stages of Trogoderma inclusum and Dermestes maculatus. Journal of Stored Products Research. 86:101556. https://doi.org/10.1016/j.jspr.2019.101556.
Quellhorst, H., Athanassiou, C.G., Bruce, A.I., Scully, E.D., Morrison III, W.R. 2020. Temperature-mediated competition between the invasive larger grain borer, Prostephanus truncatus (Coleoptera: Bostrichidae) and the cosmopolitan maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae). Environmental Entomology. 49(1):255-264. https://doi.org/10.1093/ee/nvz151.
Domingue, M.J., Morrison III, W.R., Yeater, K.M., Myers, S.W. 2020. Oleic acid emitted from frozen Trogoderma spp. larvae causes conspecific behavioral aversion. Chemoecology. 30:161-172. https://doi.org/10.1007/s00049-020-00307-3.
Gerken, A.R., Abts, S.R., Scully, E.D., Campbell, J.F. 2020. Artificial selection to a nonlethal cold stress in Trogoderma variable shows associations with chronic cold stress and body size. Environmental Entomology. 49(2):422-434. https://doi.org/10.1093/ee/nvz162.
Athanassiou, C.G., Arthur, F.H. 2020. Cool down-warm up: Differential responses of stored product insects after gradual temperature changes. Insects. 11(3):158. https://doi.org/10.3390/insects11030158.
Arthur, F.H., Athanassiou, C.G., Morrison III, W.R. 2020. Mobility of stored product beetles after exposure to a combination insecticide containing deltamethrin, methoprene, and a piperonyl butoxide synergist depends on species, concentration, and exposure time. Insects. 11:151. https://doi.org/10.3390/insects11030151.
Koch, K.G., Scully, E.D., Palmer, N.A., Geib, S.M., Sarath, G., Heng-Moss, T., Bradshaw, J.D. 2019. Divergent switchgrass cultivars modify cereal aphid transcriptomes. Journal of Economic Entomology. 112(4):1887-1901. https://doi.org/10.1093/jee/toz053.
Oppert, B.S., Chu, F., Reyna, S., Pinzi, S., Adrianos, S.L., Perkin, L.C., Lorenzen, M. 2019. Effects of targeting eye color in Tenebrio molitor through RNA interference of tryptophan 2,3-dioxygenase (vermilion): Implications for insect farming. Archives of Insect Biochemistry and Physiology. 10(1):e21546. https://doi.org/10.1002/arch.21546.
Elpidina, E.N., Semashko, T.A., Smirnova, Y.A., Dvoryakova, E., Dunaevsky, Y.E., Belozersky, M.A., Serebryakova, M.V., Klyachko, E.V., Abd El-latif, A.O., Oppert, B.S., Filippova, I.Y. 2019. Direct detection of cysteine peptidases for MALDI-TOF MS analysis using fluorogenic substrates. Analytical Biochemistry. 567:45-50. https://doi.org/10.1016/j.ab.2018.12.001.
Armisen, D., Rajakumar, R., Friedrich, M., Benoit, J.B., Robertson, H.M., Panfilio, K.A., Ahn, S., Poelchau, M.F., Chao, H., Dinh, H., Doddapaneni, H., Dugan, S., Gibbs, R.A., Hughes, D.T., Han, Y., Lee, S.L., Murali, S.C., Muzny, D.M., Qu, J., Worley, K.C., Munoz-Torres, M., Abouheif, E., Bonneton, F., Chen, T., Chiang, L.-M., Childers, C., Cridge, A., Crumiere, A.J., Decaras, A., Didion, E.M., Duncan, E.J., Elpidina, E.N., Fave, M., Finet, C., Jacobs, C.C., Jarvela, A., Jennings, E.C., Jones, J.W., Lesoway, M.P., Lovegrove, M.R., Martynov, A., Oppert, B.S., Lillico-Ouachour, A., Rajakumar, A., Refki, P., Rosendale, A.J., Santos, M., Toubiana, W., van der Zee, M., Vargas Jentzsch, I.M., Lowman, A.V., Viala, S., Richards, S., Khila, A. 2018. The genome of the water strider Gerris buenoi reveals expansions of gene repertoires associated with adaptations to life on the water. BMC Genomics. 19:832. https://doi.org/10.1186/s12864-018-5163-2.
Perkin, L.C., Oppert, B.S. 2019. Gene expression in Tribolium castaneum life stages: Identifying a species-specific target for pest control applications. PeerJ. 7:e6946. https://doi.org/10.7717/peerj.6946.
Schoville, S.D., Chen, Y.H., Childers, A.K., Childers, C., Oppert, B.S., Perkin, L.C., Poelchau, M.F., Rinehart, J.P., Yocum, G.D., Richards, S. 2018. A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae). Scientific Reports. 8(1):1931. https://doi.org/10.1038/s41598-018-20154-1.
Hubhachen, Z., Jiang, H., Schlipalius, D., Park, Y., Guedes, R.C., Oppert, B.S., Opit, G., Phillips, T.W. 2019. A CAPS marker for determination of strong phosphine resistance in Tribolium castaneum from Brazil. Journal of Pest Science. https://doi.org/10.1007/s10340-019-01134-4.
Hancock, T., Lee, D., Bergh, C., Morrison III, W.R., Leskey, T.C. 2018. Presence of the invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) on home exteriors during the autumn dispersal period: results generated by citizen scientists. Agricultural and Forest Entomology. 21:99-108. https://doi.org/10.1111/afe.12312.
Cordeiro, E.G., Campbell, J.F., Phillips, T.W., With, K.A. 2018. Behavioral and social mechanisms behind pattern formation: An experimental study of animal movement. Ecology. 33(11):1881-1894. https://doi.org/10.1007/s10980-018-0713-1.
Morrison III, W.R., Larson, N.R., Brabec, D.L., Zhang, A. 2019. Methyl benzoate as a putative alternative, environmentally-friendly fumigant for the control of stored product insects. Journal of Economic Entomology. 112(5):2458-2468. https://doi.org/10.1093/jee/toz179.
Yao, J., Chen, C., Wu, H., Chang, J., Silver, K., Campbell, J.F., Arthur, F.H., Zhu, K. 2019. Differential susceptibilities of two closely-related stored product pests, the red flour beetle (Tribolium castaneum) and the confused flour beetle (Tribolium confusum), to five selected insecticides. Journal of Stored Products Research. 84:101524. https://doi.org/10.1016/j.jspr.2019.101524.
Arthur, F.H., Starkus, L.A., McKay, T. 2019. Degradation and residual efficacy of cyfluthrin as a surface treatment for control of Tribolium castaneum Herbst: effects of temperature and environment. Journal of Stored Products Research. 84:101514. https://doi.org/10.1016/j.jspr.2019.101514.
Athanassiou, C.G., Kavallieratos, N.G., Brabec, D.L., Oppert, B.S., Guedes, R.C., Campbell, J.F. 2019. From immobilization to recovery: Towards the development of a rapid diagnostic indicator for phosphine resistance. Journal of Stored Products Research. 80:28-33. https://doi.org/10.1016/j.jspr.2018.10.004.
Oppert, B.S., Perkin, L.C., Lorenzen, M., Dossey, A.T. 2020. Transcriptome analysis of life stages of the house cricket, Acheta domesticus, to improve insect crop production. Scientific Reports. 10:3471. https://doi.org/10.1038/s41598-020-59087-z.
Scheff, D.S., Arthur, F.H., Myers, S.W. 2019. Evaluation of methoprene-treated packaging against Trogoderma granarium Everts and Trogoderma inclusum LeConte larval development and packaging penetration or invasion. Journal of Stored Products Research. 84:101530. https://doi.org/10.1016/j.jspr.2019.101530.
Rojas, L., Scully, E.D., Enders, L., Timm, A.E., Sinha, D.K., Smith, C. 2020. Comparative transcriptomics of Diuraphis noxia and Schizaphis graminum fed wheat plants containing different aphid-resistance genes. PLoS One. 15(5):e0233077. https://doi.org/10.1371/journal.pone.0233077.
Oppert, B.S., Stoss, S.P., Monk, A.L., Smith, T.P. 2019. Optimized extraction of insect genomic DNA for long-read sequencing. Methods and Protocols. 2(4):89. https://doi.org/10.3390/mps2040089.
Sparks, M., Gundersen, D.E., Bansal, R., Oppert, B.S., Poelchau, M.F., Childers, C., Rhoades, J.H., Velamuri, A.S., Benoit, J.B., Chao, H., Blackburn, M.B., Johnston, J. 2020. Brown marmorated stink bug, Halyomorpha halys (Stål), genome: underpinnings of polyphagy, insecticide resistance potential and biology of a top worldwide pest. BMC Genomics. https://doi.org/10.1186/s12864-020-6510-7.
Ludwick, D.C., Morrison III, W.R., Acebes-Doria, A.L., Agnello, A.M., Bergh, J., Buffington, M.L., Hamilton, G.C., Harper, J.K., Hoelmer, K.A., Krawczyk, G., Kuhar, T.P., Pfeiffer, D.G., Nielsen, A.L., Rice, K.B., Rodriguez-Saona, C., Shearer, P.W., Shrewsbury, P.M., Talamas, E.J., Walgenbach, J.F., Wiman, N.G., Leskey, T.C. 2020. Invasion of the brown marmorated stink bug (Hemiptera: Pentatomidae) into the USA: developing a national response to an invasive species crisis through collaborative research and outreach efforts. Journal of Integrated Pest Management. 11(1):1-16. https://doi.org/10.1093/jipm/pmaa001.
Weber, D.C., Morrison III, W.R., Khrimian, A., Rice, K.B., Short, B.D., Herlihy, M.V., Leskey, T.C. 2019. Attractiveness of pheromone components with and without the synergist, methyl (2E,4E,6Z)-decatrienoate, to brown marmorated stink bug, Halyomorpha halys (Stål) [Hemiptera: Pentatomidae]. Journal of Economic Entomology. 113:712-719.
Arthur, F.H., Bean, S.R., Smolensky, D., Gerken, A.R., Siliveru, K., Scully, E.D., Baker, N.J. 2020. Development of Tribolium castaneum (Herbst)(Coleoptera: Tenebrionidae) on sorghum milling fractions. Journal of Stored Products Research. 87:101606. https://doi.org/10.1016/j.jspr.2020.101606.
Dissanayaka, D.K., Sammani, A.P., Wijayaratne, W.K., Rajapakse, R.S., Hettiarachachi, S., Morrison III, W.R. 2020. Effects of aggregation pheromone concentration and distance on the trapping of Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) adults. Journal of Stored Products Research. 88:101657. https://doi.org/10.1016/j.jspr.2020.101657.
Arthur, F.H., Morrison III, W.R. 2020. Methodology for assessing progeny production and grain damage on commodities treated with insecticides. Agronomy. 10:804. https://doi.org/10.3390/agronomy10060804.
Dunaevsky, Y.E., Tereshchenkova, V.F., Oppert, B.S., Belozersky, M.A., Filippova, I.Y., Elpidina, E.N. 2020. Human proline specific peptidases: a systemic analysis. Biochimica et Biophysica Acta. 1864(9):129636. https://doi.org/10.1016/j.bbagen.2020.129636.
Wilkins, R.V., Zhu, K., Campbell, J.F., Morrison III, W.R. 2020. Mobility and dispersal of two cosmopolitan stored-product insects are adversely affected by long-lasting insecticide netting in a life stage-dependent manner. Journal of Economic Entomology. 113(4):1768-1779. https://doi.org/10.1093/jee/toaa094.
Scheff, D.S., Campbell, J.F., Arthur, F.H., Zhu, K. 2020. Effects of aerosol insecticide application location on patterns of residual efficacy against Tribolium confusum (Coleoptera: Tenebrionidae) larvae. Journal of Economic Entomology. 113(4):2007-2015. https://doi.org/10.1093/jee/toaa103.
Koch, K.G., Palmer, N.A., Donze-Reiner, T., Scully, E.D., Seravalli, J., Amundsen, K., Twigg, P., Louis, J., Bradshaw, J.D., Heng-Moss, T., Sarath, G. 2020. Aphid-responsive defense networks in hybrid switchgrass. Frontiers in Plant Science. 11:1145. https://doi.org/10.3389/fpls.2020.01145.