Distance-based decision making in oviposition by Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) on low- and no-gluten flours

Authors: GERKEN, ALISON - US Department Of Agriculture (USDA); DRYER, DANIELLE - US Department Of Agriculture (USDA); CAMPBELL, JAMES - US Department Of Agriculture (USDA)

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2022
Publication Date: 1/24/2023
Citation: Gerken, A.R., Dryer, D., Campbell, J.F. 2023. Distance-based decision making in oviposition by Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) on low- and no-gluten flours. Journal of Economic Entomology. 116(2):605-614. https://doi.org/10.1093/jee/toad003.
DOI: https://doi.org/10.1093/jee/toad003

Interpretive Summary: In recent years the use of low- and no-gluten flour alternatives has been increasingly used in food products. Traditional wheat flour is susceptible to a variety of insect pests, red flour beetle being one of the major pest species, but less is known about the susceptibility of these wheat flour alternatives. In previous research we found that a variety of these alternative flours were suitable for egg laying and development when female red flour beetles were presented with the flours in a no choice tests. Here we test whether female red flour beetles exhibit preference for different types of flour using both small- and large-scale choice tests as well as the level of attraction to different flour types. We found that female red flour beetles laid similar numbers of eggs in buckwheat, teff, millet, rice, and rye flour compared to wheat flour, and that females responded positively to odors from these flours. Alternatively, females laid significantly fewer eggs in cassava, oat, amaranth, potato, and garbanzo flours compared to wheat and showed less preference to move toward these flours compared to wheat flour. These results suggest that some flours are more at risk for red flour beetle infestation (buckwheat, teff, millet, rice, and rye) than others (cassava, oat, garbanzo, amaranth, and potato). Comparing the egg laying and preference tests to developmental success on the selected flour, we find that females are sometimes prioritizing egg laying in flours that lead to successful development such as spelt, teff, and buckwheat, but that females also sometimes prefer to lay eggs in flours that result in low adult progeny success, like amaranth and rice. This suggests that the beetles have limited ability to make adaptive food selections for egg laying. Further analysis of the chemical and physical properties associated with preferred and non-preferred flours can provide information on cues associated with egg laying that could be exploited in pest management programs.

Technical Abstract: The increasing popularity of low- and no-gluten flours as wheat flour alternatives has driven the need to understand risks of insect pest infestation in these products. Previous research using no-choice bioassays found that the red flour beetle, Tribolium castaneum Herbst can oviposit and develop on a range of alternative flours; here we test T. castaneum preference by assessing attraction in a wind tunnel assay and oviposition preference in both small- and large-scale choice assays between alternative and wheat flour. Some flours such as buckwheat, teff, millet, rice, and rye elicit similar responses as wheat flour for both attraction and oviposition. Other flours such as cassava and oat were not preferred for either oviposition or attraction behaviors. Flours like sorghum and amaranth, had mixed preferences for oviposition, with decreased oviposition in the small arena but not the large arena. Comparisons to published developmental success rates of T. castnaeum on these diets indicate that females can choose diets on which they have high developmental success, such as buckwheat or teff, and avoid flours like cassava where developmental success is low. However, mismatch of oviposition preference and developmental success also occurs, in flours such as rice and amaranth. These results suggest the red flour beetle has limited ability to make adaptive food selections for egg laying. Further analysis of the chemical and physical properties associated with preferred and non-preferred flours can provide information on cues associated with egg laying as well as how these cues could be exploited in pest management programs.