Understanding trichopria drosophilae performance in laboratory conditions

The recent worldwide interest in the invasive pest Drosophila suzukii (Matsumura) has risen the interest to its biological control agents. Among the parasitoids, Trichopria drosophilae (Perkins) is a cosmopolitan species found in association with the pest in different countries. As different populations of the parasitoid can adapt to different geographical areas, this study is focused to deepen the effect of temperature and host on an Italian population. The performance of T. drosophilae was studied under controlled conditions at seven constant temperatures (5-40 °C), and on two hosts, the native Drosophila melanogaster (Meigen) and the invasive D. suzukii. Information on survival, oviposition and sex ratio were acquired for all temperatures. A GLM analysis showed the influence of temperature and host species on the biological parameters analysed. The best performance in terms of fertility and offspring production were obtained between 25 and 30 °C, while the upper thermal limit for the adult survival was identified at 40 °C. Finally, two equations useful to help predictive models have been obtained. We conclude that T. drosophilae has the potential to be efficiently mass-reared at 25 °C.