Impact of irradiated Drosophila melanogaster pupae on the quality and population parameters of Trichopria drosophilae

Trichopria drosophilae is a globally distributed pupal parasitoid that
targets various species within the Drosophilidae family, including the
invasive Drosophila suzukii. The mass rearing of T. drosophilae
is a crucial step in ensuring their successful application for field D.
suzukii. control. The pupae of Drosophila melanogaster are currently used
as a host for the mass rearing of T. drosophilae. The impact of utilizing
irradiated pupae on T. drosophilae was investigated. 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 T.
drosophilae, all of which were significantly lower than those in the
normal group. However, there was no significant difference in parasitism
rate, body size, offspring eclosion rate, offspring number, and offspring
sex ratio between F2 T. drosophilae emerging from the two types of
Drosophila pupae. Compared to F2, F1 had a significantly higher net
reproductive rate (R₀, t49 = 19.07, P < 0.01), mean generation time
(T, t49 = 146.26, P < 0.01), and doubling time (DT, Z = -6.20, P
< 0.01), while the intrinsic rate of increase (r, Z = -6.28, P
< 0.01) was significantly lower. Using irradiated D. melanogaster
pupae provides an efficient method for the mass rearing of T. drosophilae
and offers valuable insights into its potential effectiveness in field D.
suzukii control.