ZcKr-h1 Knockdown Impairs Female Reproduction and Lifespan in Zeugodacus cucurbitae Under Normal and Short-Term High Temperature.

Short-term high temperature is a critical environmental factor affecting the population dynamics of invasive insect pests. Krüppel-homolog 1 (Kr-h1) is a key transcription factor involved in insect reproduction. In this study, we investigated the role of ZcKr-h1 in female reproduction and lifespan under normal and short-term high-temperature conditions in the melon fly, Zeugodacus cucurbitae (Coquillett). RNA interference (RNAi)-mediated knockdown of ZcKr-h1 markedly reduced female fecundity, shortened the oviposition period, delayed ovarian development, and decreased adult lifespan. Moreover, ZcVgR (vitellogenin receptor) expression was consistently suppressed following ZcKr-h1 knockdown at both 25 °C and 45 °C, while ZcVg3 expression was upregulated at 25 °C but showed no significant change at 45 °C. These findings demonstrate that ZcKr-h1 is essential for female reproduction and survival under both normal and short-term high-temperature conditions, and that VgR is the primary downstream effector mediating its reproductive functions. This study provides a potential molecular target for environmentally friendly pest management during hot seasons.