| Egg parasitoids of the genus Trichogramma are widely used in biological control against Lepidopterous pests. In considering future development of biological control, the focus should be placed on the applied basic research and the development of some key technologies. However, an insufficiency of basic research on Trichogramma wasps in China shows unconformity with its leading place in the world on application. This paper based on the present state of Trichogramma research, used main Trichogramma species of researching and applying in China as the studying target, aimed at key issues on influence of environmental factors in field, cold storage, species identification and non-target effect, studied concretely effects of high temperature shocks on Trichogramma dendrolomi reared on Antheraea pernyi eggs, effect of pollen of regular cotton and transgenic Cry1Ac+CpTI cotton on reproduction and survival of the parasitoid wasp Trichogramma chilonis, effects of cold storage on T. dendrolomi reared on A. eggs , system and application of molecular identification based on species-specific primers for important Trichogramma species in China, prefenence of Trichogramma dendrolimi and Trichogramma chilonis for eggs of predatory insects. The main results were summarized as follows:1 Effects of high temperature shocks on Trichogramma dendrolomi reared on Antheraea pernyi eggsTrichogramma wasps reared on Antheraea pernyi eggs have been widely used throughout China as biological control agent against some pests. However, in certain regions, high temperature prevailing in summer is suspected to execute a negative influence on the parasitoids. To simulate these adverse conditions, we applied single heat shocks (35℃ and 40℃) for 6 hours to middle stage and late stage of pupae of Trichogramma dendrolomi, and recorded the percentages of adult emergence rate, number of wasps per host egg, female ratio and longevity as well as the number of wasps with parasitization, percent emergence, number of wasps per host egg and female ratio in the next generation. The results showed the susceptibility of both middle stage and late stage of pupae to high temperature shocks, especially at 40℃. At this temperature, percent emergence and number of wasps per host egg were substantially reduced, and especially when the parasitoids experienced the high temperature shocks at late pupal stage, they nearly failed to achieve any emergence. For the progeny generation, all parameters as a whole seem to be little affected by the heat shock experienced in the parent generation.2 Effect of Pollen of regular cotton and transgenic Cry1Ac+CpTI cotton on reproduction and survival ofthe parasitoid wasp Trichogramma chilonisThe availability and quality of food played an important role in determing the effectiveness of parasitoids as control agents. The effects of pollen of regular cotton and transgenic Cry1Ac+CpTI cotton as a food source for Trichogramma chilonis were assessed in the laboratory by investigating paratization rate, prgeny survival and sex ratio. The results of this study under laboratory conditions are then considered in relation to determine whether pollen availability is likely to be an important factor in field performance and whether transgenic cotton pollen could affect survival and reproduction of T. chilonis. Females fed on a suspension of pollen of regular cotton or transgenic Bt+CpTI cotton in water lived as long as those fed on water alone or urfed, but significantly shorter than than those fed on honey alone and suspension of pollen of regular cotton or transgenic Bt+CpTI cotton in honey, either with or without eggs rice moth (Corcyra cephalonica). T. chilonis females fed on suspension of pollen of regular cottonor transgenic Bt+CpTI cotton in honey parasitized and produced significantly more eggs, offspring and males than those fed on honey or water alone, suspention of pollen of regular cotton or transgenic Bt+CpTI cotton in water and unfed. T. chilonis females fed on honey parasitized and produced significantly more eggs, offsping and males th... |
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