The series of stereotypical physiological and behavioral changes that female in-sects exhibit after mating are called postmating responses (PMR).Wolbachia are widespread intracellular bacteria that are well known for their ability to manipulate the hosts reproductive behavior to facilitate their own maternal spreading.The effect of Wolbachia infection on insect hosts PMR is not well understood.Here we showed that after mating with male Drosophila mela-nogaster infected with Wolbachia,the uninfected female showed a significant decrease in egg laying on the first day.Furthermore,both Wolbachia-infected and uninfected females mated with infected males exhibited reduced feeding frequency,low receptivity to remating,and an extended median life span compared to those mated with uninfected males.To determine how Wolbachia triggered these alterations,we detected the influence of Wolbachia infection on the expression of some genes encoding seminal fluid proteins (Sfps) in D.melanogaster.These se-minal fluid proteins are known to contribute to PMR upon transfer to females during copula-tion.We found that Acp26Aa,CG1656 and CG42474 were significantly downregulated in Wol-bachia-infected males,whereas SP,CC1652,CG9997,and CG17575 showed no significant difference between Wolbachia-infected and uninfected males.These results suggest that by de-creasing the expression of some Sfps in the male hosts,Wolbachia may modulate sexual conflicts of their insect hosts in a way favoring females,thus benefit their own transmission through host populations.This study provides new insights into the host-endosymbiont interac-tion,which may support the application of endosymbionts for the control of pests and disease vectors.