Biocontrol characteristics of the fruit fly pupal parasitoid Trichopria drosophilae (Hymenoptera: Diapriidae) emerging from different hosts.

Trichopria drosophilae (Hymenoptera: Diapriidae) is an important pupal endoparasitoid of Drosophila melanogaster Meigen (Diptera: Drosophilidae) and some other fruit fly species, such as D. suzukii, a very important invasive and economic pest. Studies of T. drosophilae suggest that this could be a good biological control agent for fruit fly pests. In this research, we compared the parasitic characteristics of T. drosophilae reared in D. melanogaster (TDm) with those reared in D. hydei (TDh). TDh had a larger size than TDm. The number of maximum mature eggs of a female TDh was 133.6 ± 6.9, compared with the significantly lower value of 104.8 ± 11.4 for TDm. Mated TDh female wasp continuously produced female offspring up to 6 days after mating, compared with only 3 days for TDm. In addition, the offspring female ratio of TDh, i.e., 82.32%, was significantly higher than that of TDm, i.e., 61.37%. Under starvation treatment, TDh survived longer than TDm. TDh also survived longer than TDm at high temperatures, such as 37 °C, although they both survived well at low temperatures, such as 18 °C and 4 °C. Old-age TDh females maintained a high parasitism rate and offspring female ratio, while they were declined in old-age TDm. Overall, TDh had an advantage in terms of body size, fecundity, stress resistance ability and the parasitism rate compared with TDm. Therefore, T. drosophilae from D. hydei could improve biocontrol efficacy with enormous economic benefits in the field, especially in the control of many frugivorous Drosophilidae species worldwide.