Life-history and host preference of Trichopria drosophilae, a pupal parasitoid of spotted wing drosophila

Trichopria drosophilae is a cosmopolitan pupal parasitoid that attacks many species of Drosophilidae, including the invasive Drosophila suzukii. This study reports on the life-history traits and host preferences of a Californian population of T. drosophilae and compares its life-time fecundity with a South Korean population of T. drosophilae. Female parasitoids emerge with a high mature egg-load (47.6 ± 2.3 eggs per female). The number of mature eggs of female T. drosophilae was affected by the female age and body size but not by the interaction between these two factors. The parasitoid did not show preference among differently aged (1–4 days old) D. suzukii pupae and host age did not affect the parasitoid’s fitness, except that offspring developmental time slightly increased with host age. In a choice test, more offspring successfully developed from the larger D. suzukii than the smaller D. melanogaster, and adult females reared from D. suzukii were larger than those that were reared from D. melanogaster, apparently at no cost in parasitoid fitness. T. drosophilae females from the Californian and the South Korean populations survived 27.5 and 20.2 days, produced a total of 63.8 and 52.0 offspring, and had an intrinsic rate of increase of 0.124 and 0.113, respectively, when provided with adult food and D. suzukii pupae as host material.