Effect of body weight on reproductive performance of Micromus tasmaniae (Walker) (Neuroptera: Hemerobiidae)

摘要

Micromus tasmaniae Walker is an important predator of a number of economically important pests such as aphids. The 'larger-the-better theory predicts that reproductive fitness is positively linearly associated with body size or weight. To test whetherlarger insects perform better reproductively, the insect population was divided into three weight groups: light, average and heavy, and the reproductive performance of nine breeding treatments (three male weights x three female weights) was assessed. The body weight of female M. tasmaniae had no significant effect on reproductive fitness in terms of fecundity, fertility, fertility rate, oviposition period and longevity, suggesting that female size variation is of secondary importance in determining reproductive fitness in this species. Male size had significant positive effect on female fecundity, fertility and fertility rate and reproductive period. This suggests that heavy males may transfer larger ejaculates that provide more sperm and male-derivednutrients to females than light males.