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 (TD(m)) with those reared in D. hydei (TD(h)). TD(h) had a larger size than TD(m). The number of maximum mature eggs of a female TD(h) was 133.6 ± 6.9, compared with the significantly lower value of 104.8 ± 11.4 for TD(m). Mated TD(h) female wasp continuously produced female offspring up to 6 days after mating, compared with only 3 days for TD(m). In addition, the offspring female ratio of TD(h), i.e., 82.32%, was significantly higher than that of TD(m), i.e., 61.37%. Under starvation treatment, TD(h) survived longer than TD(m). TD(h) also survived longer than TD(m) at high temperatures, such as 37 °C, although they both survived well at low temperatures, such as 18 °C and 4 °C. Old-age TD(h) females maintained a high parasitism rate and offspring female ratio, while they were declined in old-age TD(m). Overall, TD(h) had an advantage in terms of body size, fecundity, stress resistance ability and the parasitism rate compared with TD(m). 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.