Host plant signal persistence in the gut of the brown marmorated stink bug, Halyomorpha halys

Authors: HELPER, JAMES - Washington State University; Cooper, William - Rodney; BEERS, ELIZABETH - Washington State University

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2020
Publication Date: 12/2/2020
Citation: Helper, J., Cooper, W.R., Beers, E. 2020. Host plant signal persistence in the gut of the brown marmorated stink bug, Halyomorpha halys. Environmental Entomology. 50(1):202-207. https://doi.org/10.1093/ee/nvaa152.
DOI: https://doi.org/10.1093/ee/nvaa152

Interpretive Summary: Brown marmorated stink bug is an invasive pest of temperate tree fruits that is capable of feeding and developing upon a wide range of crop and non-crop hosts. This pest recently arrived in the agricultural regions of the Pacific Northwest where the majority of U.S. tree fruits are grown. The management of brown marmorated stink bug is challenging in part because of incomplete knowledge of which non-crop plants are used by the insect. Researchers at the USDA-ARS in Wapato, WA and Washington State University in Wenatchee, WA developed a method to detect plant DNA in the guts of brown marmorated stink bug, thereby allowing the researchers to determine which plants individual stink bugs fed upon prior to them being captured. The researchers found that the amount of plant DNA detected from the insects decreases after the insects are moved to a different host plant, but that the DNA can still be detected in the insect guts for at least 2 weeks. This method for molecular gut content analysis will be used by researchers to identify the dietary history of brown marmorated stink bugs captured in tree fruit orchards, which will allow them to create models that predict stink bug infestations and to develop landscape-level approaches to the management of this pest

Technical Abstract: Determining the host plant range of an invasive insect in a new environment is a key step in the development of a management strategy. As the brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), expands into agricultural regions of North America, efforts to elucidate its dietary habits on a landscape scale mostly rely upon intensive, season-long sampling of potential host plants. While this approach yields useful information, results can be biased towards plant species that are common and easily sampled; important hosts can be missed if sampling them is impractical or limited in scope. Here we lay the groundwork for the application of gut content analysis to determining the feeding ecology of H. halys by investigating the persistence of host plant DNA in the digestive tracts of insects with known feeding histories. Adult H. halys were fed lima bean plants (Phaseolus lunatus L.) for 7 days, followed by a forced host switch to carrot (Daucus carota L.). Insect guts were dissected out at 0, 1, 3, 7, and 14 days following the switch to carrot, and host plant chloroplast genes (trnF and trnL) were amplified via PCR. Amplicons were identified using high-throughput sequencing and analyzed for the persistence of Phaseolus DNA. The original host remained detectable at 3 days (trnF) and 14 days (trnL) in substantial quantities. The proportion of total reads identified as Phaseolus rapidly decreased with time; a concomitant increase in Daucus reads was observed. Our results indicate that high-throughput sequencing of gut contents has great potential for exploring the dietary histories of field-caught H. halys and other phytophagous insect pests