Identifying The Trichogramma Parasitoids And Researching Their Biological Control Potential In Guizhou

Trichogramma species were put into use widely on Lepidopterous pest control. Comparing with chemical pesticide, the advantages of Trichogramma species are specific highly, environment friendly and so on, Trichogramma is an important measure of pest control to get pollution-free agricultural products and organic agricultural production. Guizhou has a unique geographical and climatic characteristics, and the natural resource is rich, such as natural enemies of Trichogramma variety has broad prospects for development and utilization. This study aimed at the sorghum, coix seed, tea, rice, corn and other characteristics crops or other pollution-free production in Guizhou. Then collecting, purificating and identifing the Guizhouon Trichogramma population, then to study their parasitism potential, screening out the frequent Trichogramma species, mass propagation to lay the foundation of the field control and prevention. 1. Separation and identified the parasitoid wasp from eggs of Ostrinia furnacalis(Guenée)Collecting the parasite eggs of Ostrinia furnacalis(Guenée), separating parasitoid wasp from it, then identifying them according to the morphological characteristics of male genitalia. Three natural populations parasitizing eggs of Ostrinia furnacalis(Guenée) in Guizhou were found: Trichogramma.ostriniae, Trichogramma. leucaniase and Trichogramma. chilonis. 2. Analyses of parasitism potential of three indigenous Trichogramma species on Corcyra cephalonica(Stainton) eggsThe experimental population life tables on Ostrinia furnacalis(Guenée) eggs were established for each Trichogramma species reared on the eggs of rice moth, Corcyra cephalonica. The reproductive property parameters of the net reproduction rate(R0), mean generation time(T), intrinsic rate(rm), finite rate of increase(λ), number of host eggs parasitized per female, average longevity of female and emergence rate were compared and analyzed. The results showed that the R0, T, rm and λ of Trichogramma. ostriniae, Trichogramma. leucaniase and Trichogramma. chilonis on Ostrinia furnacalis(Guenée) eggs were 18.48,31.40 and 10.98,10.20,10.13 and 10.21 d,0.2861,0.3402 and 0.2346,1.3312,1.4052 and 1.2643, respectively. Generally, the reproductive property paraments(R0, T, rm and λ) of T. leucaniase were more ideal than those of T. ostriniae and T. chilonis. 3. Host selection on Ostrinia furnacalis(Guenée) eggs at different ages by Trichogramma species from different geographical populationsAccording to comparing the parasitism abilities of Trichogramma species from different geographical populations on 0-4-day-old Ostrinia furnacalis(Guenée) eggs. The results indicated that Trichogramma. ostriniae and Trichogramma. chilonis significantly preferred 0-4-day-old eggs with no difference between the different geographical populations, but the Trichogramma. leucaniase did. The T. leucaniase collected from Guiyang has better parasitism abilities than T. leucaniase collected from northeastern China on 3-day-old Ostrinia furnacalis(Guenée) eggs. 4. Parasitism and suitability of three indigenous Trichogramma species on their natural host eggs of Ostrinia furnacalis(Guenée)In this experiment, we compared the parasitic capacity and suitability of three Trichogramma species on Ostrinia furnacalis(Guenée) eggs at various ages.The results indicated that there were no signifinant differences in parasitism on the 0 and 4-day-old eggs for the three Trichogramma species all. Trichogramma. leucaniase tended to parasitize 2-to-3-day-old eggs more than they did on others.