Effects Of Elevated Temperature And CO₂ On Development And Physiological Metabolismof Bemisia Tabaci ?Hemiptera: Aleyrodidae?

Climate change involves multiple factors such as rising CO₂ concentration and global warming.The elevated CO₂ and temperature has direct and indirect effects on insect herbivores.In this study,Bemisia tabaci were reared at ambient or elevated CO₂ concentration?[CO₂],400 ppm and 800 ppm respectively?and ambient or eleveted temperature?27 ± 1oC/20 ± 1oC light/dark and 34 ± 1oC/27 ± 1oC light/dark respectively?for three generations.We investigated the effects of temperature and [CO₂]on B.tabaci development,endosymbiont,amino acids and protective enzymes.The main results are described as follows:1.Nymphal development of B.tabaci was significantly affected by [CO₂],temperature and generation,and there was a significant interactive effect between temperature and generation on total developmental time.Under ambient temperature,elevated [CO₂] markedly increased developmental time of B.tabaci,reduced nymphal size and longevity.Under elevated temperature,elevated [CO₂] significantly decreased survival rate,fecundity and longevity in the first generation.Under ambient or elevated [CO₂],elevated temperature significantly reduced survival rate,developmental time,nymphal size,fecundity and longevity of B.tabaci.2.Endosymbiont was significantly affected by [CO₂],temperature and generation.The primary endosymbiont Portiera and secondary endosymbiont Hamiltonella and Rickettsia were indentified in successive three generations of B.tabaci.Interestingly,under ambient temperature and elevated [CO₂],the secondary endosymbiont Cardinium could only be indentified in the second and third generations but not in the first generation of B.tabaci with.Under elevated temperature elevated [CO₂],the secondary endosymbiont Cardinium was indentified in all three generations of B.tabaci.At ambient [CO₂],elevated temperature reduced relative amount of Portiera?in the first generation?and Hamiltonella?in the first generation?,increased relative amount of Hamiltonella?in the third generation?.Under elevated [CO₂],elevated temperature decreased relative amount of Portiera?in the first and second generation?and Hamiltonella?in the third generation?.There was a significant interaction between [CO₂] and temperature on secondary endosymbiont Rickettsia.Elevated temperature and [CO₂] decreased relative amount of Rickettsia.3.Total amino acids in B.tabaci were significantly affected by [CO₂],temperature and their interaction.Under ambient or elevated temperature,elevated [CO₂] upgraded total amino acids in on the first and second generations of B.tabaci.Essential amino acids were significantly affected by temperature and [CO₂].Elevated [CO₂] or elevated temperature reduced proportion of essential amino acids.Besides,glutamine,alanine and proline were the most abundant free amino acids in the first and second generations of B.tabaci,while glutamine and alanine were the most abundant free amino acids in the third generation of B.tabaci.4.Temeperature,generation and their interactions have significant impact on protective enzymes in B.tabaci.Under ambient [CO₂],elevated temperature increased SOD and POD activities in the first generation,CAT activity in the second generation,decreased POD activity in the third generation and CAT activity in the first generation.At [CO₂] enhancement,elevated temperature increased SOD and CAT activities in the first generation and in the third generation,respectively;reduced POD and SOD activities in the third generation as well as CAT activity in the first generation.