A systematic review of the behavioral responses by stored-product arthropods to individual or blends of microbially-produced volatile cues

Authors: PONCE, MARCO - Kansas State University; KIM, TANIA - Kansas State University; Morrison, William - Rob

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2021
Publication Date: 4/28/2021
Citation: Ponce, M., Kim, T.N., Morrison III, W.R. 2021. A systematic review of the behavioral responses by stored-product arthropods to individual or blends of microbially-produced volatile cues. Insects. 12(5):391. https://doi.org/10.3390/insects12050391.
DOI: https://doi.org/10.3390/insects12050391

Interpretive Summary: Microbes are everywhere, including in our food after harvest. Stored-product insects have been described as attracted, repelled, or unaffected by microbial cues (odors given off by microbes in grain) in the prior published literature, but no one has systematically examined all the prior tests to determine general patterns. In reviewing 43 articles that contained 384 sets of tests on 24 stored-product pests, we found a total of five and four stored-product insects were attracted and repelled by microbial cues, respectively, while 13 were unaffected or exhibited both attraction and repellency. Overall, our results demonstrate that the behavioral responses by stored-product insects to microbial cues were complex, context-, and species-dependent, which warrants further investigation to clarify mechanisms. Ultimately, we may be able to use a subset of these odors to manipulate pest behavior to improve management of insect pests while protecting commodities after harvest.

Technical Abstract: Microbes are ubiquitous and play important ecological roles in a variety of habitats. While re-search has been largely focused on arthropods and microbes separately in the post-harvest supply chain, less attention has been paid to their interactions with each other. Up to this point, there has been no attempt to systematically describe the patterns of behavioral responses by stored-product insects to microbially-produced volatile organic compounds (MVOCs). Thus, our aims were to evaluate whether stored-product arthropods were primarily and significantly attracted, repelled, or had a net neutral effect (e.g., unaffected or mixed) by MVOCs presented as 1) complex headspace blends, or 2) single constituents and known mixtures. In total, we found 43 articles that contained 384 sets of tests with different combinations of methodology and/or qualitative findings, de-scribing the behavioral responses of 24 stored-product arthropod species from two classes, four orders, and 14 families to 58 individual microbial compounds and the complex headspace blends from at least 78 microbial taxa. A total of five and four stored-product arthropod species were significantly attracted and repelled by MVOCs across odor sources, respectively, while 13 were unaffected or exhibited mixed effects. We summarize the biases in the literature, including that the majority of tests have occurred in the laboratory with a limited subset of methodology and has largely only assessed the preference of adult arthropods. Finally, we identify foundational hy-potheses for the roles that MVOCs play for stored-product arthropods, identify gaps in research and future directions, while highlighting that the behavioral responses to MVOCs are complex, context-, and taxon-dependent, which warrants further investigation.