Studies On Post-copulatory Sexual Selection In Glenea Cantor (Fabricius)

Glenea cantor (Fabricius) is an important pest damaged the kapok tree, Gossampinus malbarica (DC.), even cause death by sceriously demaged. Base on the successful rearing of the experimental populations of G. cantor, the influences of thiotepa on the male pupa’s emergence rate, adult longevity and the ability of mating of males, females’fecundity and hatching rate after the normal female mated with sterile males which were treated by thiotepa in different stages with were studied. The sperm using strategy of a female which copulated with two males was studied by using the chemical sterile technology. Meanwhile, the sperm of ultrastructure, transmit and dynamics of the sperm in female were described. The main results were summarized as follows:1. When the larvae of G. cantor were reared by using kapok segment and rearing in tubes, the rate of pupation and emergence were more than90%, and the adult weight and living ability were the same as that of the wild population.2. There were obvious teratogenic effects to the male pupae of G. cantor treated by high concentrations of thiotepa. The early stages of pupation were most sensitive to thiotepa, when pupae were treated by the concentration of0.4%、0.8%and1.6%, the teratogenic rate were7.14%、20.00%and54.55%, respectively.3. The longevity and mating duration of males would be decreased with the increasing of concentration of thiotepa, when treated by different concentrations of thiotepa in different stages of G. cantor. The effect of thitotepa would be the greatest when treated in the early and middle pupation and the males emergence for24-36h. When treated during the early and middle pupation by1.6%concentration of thiotepa, the mean longevity of males were25.40d and27.71d, respectively. The most obvious effect on the mating duration of males was treated by thitotepa in the early pupation, and the mean mating duration of males which treated in the concentration of1.6%thitotepa was only123.75±9.44min compared with the controls which was227.50±24.87min. 4. The males would be sterile treated with the concentration of0.4%in different stages of male pupa and adult which emergence for10days, but there was no any effect on the mating behaviour of males, and the eggs laid by females mated with a treated male would not hatch.5. The results of post-copulation sexual selection showed that the sperm using strategy of female conform with "last male sperm preference", and the proportion of next offspring which belong to the last male made up88.38%.6. The sperm of G. cantor with a shape of linear and a definitely head. After mating normally, the number of sperms diverted to the bursa copulatrix female was9.65×104±3.79×103.