Parasitoid Wasps Can Manipulate Host Trehalase to the Benefit of Their Offspring.

Trehalase is an essential hydrolase of trehalose in insects. However, whether and how trehalase performs in the association of parasitoid wasps and their hosts still remains unknown. Here, the exact function of trehalase of the general cutworm after it was parasitized by its predominant endoparasitoid was elucidated. Two trehalase genes (, ) were identified, and they were highly expressed five days after parasitization by . Then, we successfully silenced and in parasitized third instar larvae. The content of glucose, which is the hydrolysate of trehalose, was significantly decreased after silencing in parasitized larvae, and the activities of trehalase were also notably reduced. In addition, the cocoon weight, the emergence rate, proportion of normal adults, and the body size of parasitoid offsprings were significantly decreased in - or -silenced groups compared to the controls. These results implied that parasitization by parasitoids regulated the trehalase of host larvae to create a suitable nutritional environment for the parasitoid offspring. The present study broadens the knowledge of trehalase in the interaction between parasitoids and their hosts and is of benefit to biological control of acting by parasitoid wasps.