Abstract: 【Aim】 Trichopria drosophilae is a pupal parasitoid which can parasitize many Drosophila species. This study aims to investigate the differential effects of hosts D. auraria, D. simulans and D. immigrans pupae on the fitness of female and male adults of T. drosophilae. 【Methods】 D. auraria, D. simulans and D. immigrans pupae were respectively provided to adult T. drosophilae to parasitize for 24 h. The emergence rate, sex ratio (male to female ratio), growth rate, developmental duration, adult body weight, adult lifespan and starvation tolerance time of female and male offspring of T. drosophilae, and the number and length of eggs in ovaries of the female adult of offspring were measured. D. auraria, D. simulans and D. immigrans pupae were respectively provided to a female adult of T. drosophilae to parasitize. The selection and oviposition behavior of female T. drosophilae on different host species were observed.【Results】 The female and male offspring of female T. drosophilae parasitized in D. immigrans pupae with heavy body weight had the highest adult body weight, the longest starvation tolerance time, and the female adult offspring had the longest lifespan and the highest number of eggs in ovaries. In the pupae of three Drosophila host species, female adult of T. drosophilae had significantly greater adult body weight than male adult of T. drosophilae, but the body weight difference between female and male T. drosophilae in D. immigrans pupae was the smallest, and that in D. auraria pupae was the largest. There was no significant difference in the starvation tolerance time between female and male offspring of T. drosophilae. The lifespan of female adult of T. drosophilae emerged from the D. aurari and D. immigrans pupae was significantly longer than that of male adult, but the lifespan of male adult of T. drosophilae emerged from D. simulans pupae was significantly longer than that of female adult of T. drosophilae. Three host species pupae had no significant effect on the emergence rate, sex ratio and oviposition preference of T. drosophilae, but female adult of T. drosophilae spent significantly more time for oviposition in a D. immigrans pupa than in the pupa of the other two Drosophila species. 【Conclusion】 The fitness of female and male offspring of T. drosophilae was significantly different in three Drosophila host species, and the fitness offspring adults in the D. immigrans pupae was the highest. Considering the different responses of the fitness of female and male wasps to host changes, the effect of host quality on population fecundity can be more accurately evaluated.

Key words: Drosophila, Trichopria drosophilae, host, body weight, starvation tolerance, lifespan