<italic>Physalis floridana</italic> suppresses the expression of trehalase gene <italic>HvTREs</italic> in <italic>Henosepilachna vigintioctopunctata</italic> (Coleoptera: Coccinellidae) for defense against herbivorous insects.

Plants use various secondary chemicals in their chemical defense against herbivores. While botanical insecticides are crucial for reducing the reliance on chemical pesticides, the development of plant-derived insecticides remains limited. In this study, we fed <italic>Henosepilachna vigintioctopunctata</italic> with three different host plants (<italic>Solanum nigrum</italic>, <italic>Solanum tuberosum</italic>, and <italic>Physalis floridana</italic>) and observed that feeding on <italic>P. floridana</italic> led to changes in the body size and a significantly high mortality rate. Through transcriptome analysis, it was found that the trehalose metabolism pathway of <italic>H. vigintioctopunctata</italic> changed significantly under different host feeding conditions, especially since the expression level of the trehalase gene was extremely different. We subsequently identified eight transcripts of <italic>HvTREs</italic> and analyzed their evolution and structure. Among them, significant differences are observed in the relative expression levels of <italic>HvTRE1-5</italic> in <italic>H. vigintioctopunctata</italic> after the fourth instar and were affected by different plant diets. Compared with the natural host<italic> S. nigrum</italic>, the larvae that fed on <italic>P. floridana</italic> significantly reduced the contents of trehalose, glucose and glycogen and significantly affected the trehalase activity. Knockdown of <italic>HvTRE1-5</italic> by RNAi increased mortality at the <italic>H. vigintioctopunctata</italic> prepupation stage, suggesting that <italic>HvTRE1-5</italic> is important for <italic>H. vigintioctopunctata</italic> pupation. This study provides new insights into developing of green control methods for <italic>H. vigintioctopunctata</italic> and offers a valuable example for understanding the interaction between host plants and herbivorous insects. [ABSTRACT FROM AUTHOR]