The suitability of combining microbial pesticides and an insect parasitoid for pest management of stored cereal in China was evaluated using laboratory assays. For this purpose, interactions between Bacillus thuringie...The suitability of combining microbial pesticides and an insect parasitoid for pest management of stored cereal in China was evaluated using laboratory assays. For this purpose, interactions between Bacillus thuringiensis （Bt）, Bt-intoxicated host larvae and the parasitoid Habrobracon hebetor （Say） （Hymenoptera： Braconidae） were tested against Plodia interpunctella Hubner （Lepidoptera： Pyralidae）. Bt or H. hebetor alone caused 41.67% and 35.35% P interpunctella larval mortality respectively. The Bt- parasitoid combined treatment significantly increased mortality ofP interpunctella （86%）. Progeny development of H. hebetor was dependent upon its susceptibility to Bt. Fewer parasitoids emerged from Bt-parasitoid combined treatment than in non-Bt treatments. However, since Bt did not prevent parasitoid development, a combined treatment with Bt and parasitoid release could produce better protection against P. interpunctella than either treatments when used singly, because their lethal effects were additive to each other.展开更多
Heat shock proteins （HSPs） are known as chaperones that help with folding of other proteins when cells are under environmental stresses. The upregulation of HSPs is essential for cold survival during insect diapause...Heat shock proteins （HSPs） are known as chaperones that help with folding of other proteins when cells are under environmental stresses. The upregulation of HSPs is essential for cold survival during insect diapause. The ectoparasitoidHabrobracon hebetor, a potential biological control agent, can enter reproductive diapause when reared at low temperature and short photoperiod. However, the expression of HSPs during diapause of H. hebetor has not been studied. In this study, we sequenced and characterized the full-length complementary DNAs of three Hsp70 genes （HhHsp70I, HhHsp70II and HhHsp70IIl） from 11. hebetor. Their deduced amino acid sequences showed more than 80% identities to their counterparts from other insect species. However, the multiple se- quence alignment among the three deduced amino acid sequences of HhHsp70s showed only 46% identities. A phylogenetic analysis of the three HhHsp70s and all other known Hsp70 sequences from Hymenoptera clustered all the Hsp70s into four groups, and the three HhHsp70s were distributed into three different groups. Real-time quantitative poly- merase chain reaction analysis showed that the expression of the three HhHspTO genes in H. hebetor reared at different conditions was quite different. HhHspTOI showed higher relative expression when H. hebetor were reared at 27.5℃ than at two lower temperatures （17.5℃ and 20℃） regardless of the photoperiod, whereas HhHspTOII showed higher ex- pression when H. hebetor were reared at 20℃ and 10 ： 14 L ： D than when reared at 17.5℃ and either 16 ： 8 L ： D or 10 ： 14 L ： D. In contrast, HhHSP7OIIIwas expressed at similar levels regardless of the rearing conditions. These results may suggest functional differences among the three HhHspTO genes in H. hebetor.展开更多
文摘The suitability of combining microbial pesticides and an insect parasitoid for pest management of stored cereal in China was evaluated using laboratory assays. For this purpose, interactions between Bacillus thuringiensis （Bt）, Bt-intoxicated host larvae and the parasitoid Habrobracon hebetor （Say） （Hymenoptera： Braconidae） were tested against Plodia interpunctella Hubner （Lepidoptera： Pyralidae）. Bt or H. hebetor alone caused 41.67% and 35.35% P interpunctella larval mortality respectively. The Bt- parasitoid combined treatment significantly increased mortality ofP interpunctella （86%）. Progeny development of H. hebetor was dependent upon its susceptibility to Bt. Fewer parasitoids emerged from Bt-parasitoid combined treatment than in non-Bt treatments. However, since Bt did not prevent parasitoid development, a combined treatment with Bt and parasitoid release could produce better protection against P. interpunctella than either treatments when used singly, because their lethal effects were additive to each other.
文摘Heat shock proteins （HSPs） are known as chaperones that help with folding of other proteins when cells are under environmental stresses. The upregulation of HSPs is essential for cold survival during insect diapause. The ectoparasitoidHabrobracon hebetor, a potential biological control agent, can enter reproductive diapause when reared at low temperature and short photoperiod. However, the expression of HSPs during diapause of H. hebetor has not been studied. In this study, we sequenced and characterized the full-length complementary DNAs of three Hsp70 genes （HhHsp70I, HhHsp70II and HhHsp70IIl） from 11. hebetor. Their deduced amino acid sequences showed more than 80% identities to their counterparts from other insect species. However, the multiple se- quence alignment among the three deduced amino acid sequences of HhHsp70s showed only 46% identities. A phylogenetic analysis of the three HhHsp70s and all other known Hsp70 sequences from Hymenoptera clustered all the Hsp70s into four groups, and the three HhHsp70s were distributed into three different groups. Real-time quantitative poly- merase chain reaction analysis showed that the expression of the three HhHspTO genes in H. hebetor reared at different conditions was quite different. HhHspTOI showed higher relative expression when H. hebetor were reared at 27.5℃ than at two lower temperatures （17.5℃ and 20℃） regardless of the photoperiod, whereas HhHspTOII showed higher ex- pression when H. hebetor were reared at 20℃ and 10 ： 14 L ： D than when reared at 17.5℃ and either 16 ： 8 L ： D or 10 ： 14 L ： D. In contrast, HhHSP7OIIIwas expressed at similar levels regardless of the rearing conditions. These results may suggest functional differences among the three HhHspTO genes in H. hebetor.
