Host‐derived lipids are required for successful embryonic development in the pupal parasitoid <i>Trichopria drosophilae</i>

Parasitoids often manipulate host nutritional metabolism to facilitate their own growth and survival. However, how parasitoids acquire and utilize host-derived nutrients to support embryonic development remains poorly understood. Here, we found that Trichopria drosophilae embryonic development depends on lipid nutrition from the dissociated fat bodies in its Drosophila host pupae. Untargeted metabolomics analysis revealed that host lipids, particularly glycerolipids and sphingolipids, might be important for T. drosophilae embryogenesis. We further identified eight lipophorin receptors in T. drosophilae, among which TdOGS08990 exhibited the highest expression during the egg stage. RNA interference (RNAi)-mediated knockdown of TdOGS08990 significantly disrupted embryonic development, revealing its essential role in transporting host-derived lipids for parasitoid embryogenesis. These results advance our understanding of parasitoid-host nutritional ecology, demonstrating that lipid acquisition from hosts is a fundamental requirement for embryonic development in parasitoids.