Impact of Irradiated Drosophila melanogaster Pupae on the Quality and Population Parameters of Trichopria drosophilae

<i>Trichopria drosophilae</i> is a globally distributed pupal parasitoid that targets various species within the Drosophilidae family, including the invasive <i>Drosophila suzukii</i>. The mass rearing of <i>T. drosophilae</i> is a crucial step in ensuring their successful application for field <i>D. suzukii</i> control. The pupae of <i>Drosophila melanogaster</i> are currently used as a host for the mass rearing of <i>T. drosophilae</i>. After irradiation, the immune system function of <i>Drosophila</i> pupae was weakened, leading to an increase in the parasitism efficiency of the <i>T. drosophilae</i>. Our results showed that irradiated pupae had a significant impact on the parasitism rate, offspring eclosion rate, offspring number, and female body size of F1 <i>T. drosophilae</i>, all of which were significantly lower than those in the normal group. However, there was no significant difference in the parasitism rate, body size, offspring eclosion rate, offspring number, or offspring sex ratio between F2 <i>T. drosophilae</i> emerging from treated or untreated <i>Drosophila</i> pupae. Compared with F2, F1 had a significantly higher net reproductive rate (<i>R₀</i>), mean generation time (<i>T</i>), and doubling time (<i>DT</i>), while the intrinsic rate of increase (<i>r</i>) was significantly lower. Using irradiated <i>D. melanogaster</i> pupae provides an efficient method for the mass rearing of <i>T. drosophilae</i> and offers valuable insights into its potential effectiveness in field <i>D. suzukii</i> control.