BACKGROUND: Megabruchidius dorsalis, an oligophagous seed beetle, exhibits critical host selection behaviors that directly influence its survival. This study investigated the host preferences of both adults and larvae among three Gleditsia species G. heterophylla (Gh), G. sinensis (Gs), and G. japonica (Gj) through choice experiments, and examined the roles of visual, gustatory and olfactory cues in host selection. Life table analyses also were conducted to assess developmental outcomes across hosts, linking preference patterns to fitness consequences. RESULTS: Larvae strongly preferred feeding on Gh. However, regardless of the integrity of antennae or the lighting conditions of the environment, adult insects consistently oviposit on the surface of Gs. Pearson correlation analysis combined with partial least squares regression revealed a strong association between adult oviposition and host phenotypic traits as well as key volatile organic compounds. By contrast, larval feeding behavior was primarily influenced by host nutritional content. Life table analysis indicated that development on Gs was significantly prolonged, whereas Gh supported the highest reproductive output, as reflected by superior net reproductive rates. CONCLUSION: M. dorsalis exhibits distinct stage-specific sensory adaptations in host selection. Adults use visual and olfactory cues to choose oviposition sites. Larvae select hosts based on nutritional quality for better growth and development. This difference represents an ecological trade-off between reproduction and larval development. © 2026 Society of Chemical Industry.
Li et al. (Mon,) studied this question.