Effect Of Copper And Cadmium Stress On Development And Reproduction Of Nasonia Vitripennis (Hymenoptera: Pteromalidae)

In this paper, effects of Cu²⁺ and Cd²⁺ stress on development and reproduction of Nasonia vitripennis through a parasite food chain were studied, based on the relationship between.susceptible strain (S) and resistant strain (CuR) of flesh fly Boettcherisca (Sarcophaga) peregrina and their pupae parasitoid N. vitripennis. The results are shown as follows.1. Effect of copper stress on development and reproduction of Nasonia vitripennisCu²⁺ stress on susceptible strain (S) and resistant strain (CuR) of flesh fly influenced development and reproduction of their pupae parasitoid N. vitripennis indirectly. Parasitism rate and oviposition number of parent generation increased at low dose but decreased at high dose, moreover, data in CuR treatments were much higher than those in S treatments. Cu²⁺enhanced oviposition number per weight of fleshfly pupa, while reduced eclosion rate and adult longevity of F₂ generation, especially in CuR treatments. In addition, Cu²⁺ stress, especially in high concentration treatment, changed sexal ratio of F₁ and F₂ generation.2. Effect of cadmium stress on development and reproduction of Nasonia vitripennisCd²⁺ stress on susceptible strain (S) and resistant strain (CdR) of flesh fly influenced development and reproduction of their pupae parasitoid N. vitripennis indirectly. Parasitism rate of parent generation increased at low dose but decreased at high dose. Moreover, Cd²⁺ enhanced oviposition number per weight of fleshfly pupa of parent generations, influenced body weights in different development stages of F\ generation, and reduced eclosion rate and larva-pupa development duration of F\ generation. These effects were more obvious in CdR treatments, but could not transfer to the next generation. In addition, Cd²⁺ stress, especially in high concentration treatment, changed sexal ratio of F₁ and F₂ generation. 3. Effect of copper on Vitellogenesis in Nasonia vitripennisNewly emerging N. vitripennis female adults which never touched copper before were fed with Cu²⁺ in 20% saccharose solution, thus their ovarian Vt decreased significantly, which meant Cu²⁺ inhibited Vg uptake. And, ovarian Vt of N. vitripennis which emerged from susceptible strain pupae of flesh fly treated with high dose also decreased significantly, while hemolymph Vg decreased markedly. All the results indicated, copper also inhibited Vg synthesis in N. vitripennis.