Effects Of Long-term Acclimation On Response Temperature And Imidacloprid Interaction Of Rhopalosiphum Padi

Global warming and pesticide pressure have had a significant impact on the earth’s organisms,and the assessment of its ecological consequences has become a global hot spot.In the farmland ecosystem,the interaction between high temperature and pesticide is more and more obvious.Therefore,response of physiological tolerance and core life parameters of wheat pest Rhopalosiphum padi to high temperature and imidacloprid after different long-term acclimation(Control population CK;High temperature population HP,and Imidacloprid population IP).The results lay a theoretical foundation for the population ecological mechanism of R.padi under high temperature or pesticide environment,also,it has important guiding significance for biodiversity conservation and integrated pest management in current and future climate change scenarios.The main research results show that:1 Effects of long-term acclimation and sub-lethal high temperature treatment on Rhopalosiphum padi.Sub-lethal high temperature treatment treatment(27℃)had different effects on environmental tolerance and life history traits of R.padi populations with different long-term acclimation.In general,the sensitivity of R.padi to imidacloprid decreased gradually at 27℃,and IP was the most obvious.The LC50 of imidacloprid in CK was 339.699 μg/m L at 22℃,and 510.658 μg/m L at 27℃ while the LC50 of imidacloprid in IP was 966.039 μg/m L at 22℃ and 1629.123 μg/m L at 27℃.Similarly,the tolerance of R.padi to high temperature gradually increased at 27℃,and HP showed the best effect.The CTmax of 27℃treatment increased by 0.57℃ compared with 22℃,which benefits the long-term domestication.However,high temperature treatment had no significant effect on low temperature tolerance of populations with different long-term acclimation.At the same time,high temperature treatment also had some negative costs on life history traits of populations with different long-term acclimation.The development period of the three populations experienced in long-term acclimation was shortened by 0.37 d,0.44 d,and 1.62 d respectively at 27℃,and the survival rate of CK decreased by 22.22%.It also had a certain negative impact on adult traits,and the lifespan of adults of IP was significantly extend at 22℃.In general,high temperature treatment promoted the population parameters of HP and IP,but inhibited the population parameters of CK.2 Effects of long-term acclimation and imidacloprid on Rhopalosiphum padi.Whether imidacloprid P treatment or not,HP had no obvious interactive effect on imidacloprid sensitivity and IP temperature tolerance,while IP had an adaptive phenomenon to pesticide sensitivity and HP had a high temperature tolerance.The LC50 of IP was 966.039 μg/m L and that of P treatment was 1623.801 μg/m L at P-.While the CTmax of HP in P+ treatment was 1.05℃ higher than that at P-.Moreover,imidacloprid also had different inhibition effect on population life history traits of different long-term acclimation.Under imidacloprid P+treatment,HP and CK significantly inhibited the development duration of nymph aphid compared with the corresponding population at P-,which respectively prolonged by 1.83 d and 1.96 d,And eventually,the population parameters are decreased,which showed that aphids increase heat resistance and invest less energy in development.But the IP was different.The development period was significantly shortened by2.45 d under imidacloprid P+ treatment compared with that of at P-.Furthermore,the survival rate of different long-term acclimation population were all decreased after imidacloprid P+ treatment.The survival rate of IP was significantly lower than that of CK at P-.Moreover,IP had brought a serious cost to its adult traits: the life span of the plant was significantly prolonged,the reproduction was reduced at P-,and the life span and reproduction were reduced under imidacloprid P+ treatment.3 Effects of long-term acclimation and high temperature combined with imidacloprid on Rhopalosiphum padi.The sensitivity to imidacloprid was decreased in the P+27℃ treated with different long-term acclimation.For example,the LC50 of HP was 374.606 μg/m L at P-22℃,and 981.429 μg/m L at P+27℃,the LC50 of IP was 966.039 μg/m L at P-22℃ and that of P+27℃ was1496.518 μg/m L.The response of populations with different long-term acclimation to high temperature tolerance was also different under the combined treatment of P+27℃.The CTmax of CK was significantly decreased at P+27℃ while the CTmax of HP and IP were increased,but not significantly.High temperature combined with imidacloprid had no effect on the cold tolerance of different long-term acclimation populations.In addition,R.padi not only benefit from tolerance,but also negatively affect its life history traits.It showed that the nymph development duration of CK was prolonged by 0.27 d,the survival rate was decreased by18.05%,the life span was shortened by 6.32 d and the reproduction was reduced by 6.72 per female compared with 22℃.The life span of HP was shortened by 6.24 days and the reproduction was reduced by26.72 per female.Interestingly,compared with CK,the developmental duration and life span of IP respectively increased by 1.55 d and 5.58 d,and the reproductive capacity of IP decreased by 7.15 per female.Compared with CK,the development duration of IP was significantly shortened by 1.25 d in P+27℃,but the increase of IP reproduction was significantly stimulated by P+27℃.In general,P27℃treatment inhibited the population parameters of CK and HP,and promoted the population parameters of IP.