Study On Host Sources Of Ostrinia Furnacalis (Guenée) Based On Carbon Stable Isotope Technique

Asian corn borer?ACB?[Ostrinia furnacalis?Guenée?]is the most important insect of corn in China,which damage pose a serious threat to corn quality and food security.The host plants of ACB are widely distributed.Host plants have an important influence on the population dynamics of Asian corn borer.The aim of our study is to determine the food source and the percentage of ACB feeding on C₃and C₄ host plants during their larvae stage,and to research the refuge role of non-corn host plants in for target insect pest resistance management of transgenic Bt corn.In the end,we will reduce the difficulty of integrated pest management.To solve the above problem,this article implemented the following experiment.First,Researching the variation of the?¹³C value of ACB feeding on different host plants;Secondly,From 2015 to 2017,we monitor the dynamics of population of ACB in Northwest Irrigation Corn Region,Northern Spring Sowing Corn Region and Huang-Huai-Hai Summer Corn Region,including 7 provinces and 14 districts;Thirdly,Tracking their host plant origins as larvae via the technique of stable carbon isotope.The results are as follows.The?¹³C value of wings of ACB is higher than that of the host plants which eaten by its larvae,and the date can accurately reflect whether the larva fed on C₃ or C₄ plants;The food types of the adult stage have no influence to the?¹³C value of ACB.In Northwest Irrigation Corn Region?New city district,Chabuchar,Shule?,ACB occur 3generations a year;In Huang-Huai-Hai Summer Corn Region?Wenshang,Zhangqiu,Anyang,Yuanyang?,ACB occur 3 generations a year;In Northern Spring Sowing Corn Region?Harqin Banner,Gongzhuling,Taonan,Dunhua,Shuangcheng?,ACB occur 1² generations a year.In 2015,the average number of C₃ host plants of overwintering,first generation and second generation ACB adults in different regions was 7.48%,7.29%and 0.21%respectively.In Northwest Irrigation Corn Region,Northern Spring Sowing Corn Region and Huang-Huai-Hai Summer Corn Region,the proportion of overwintering generation of ACB feeding on C₃ plant is less than 25%.And,the percentage of first generation of ACB feeding on C₃ plant ranged from 0 to 12.50%.In Changtu,29.23%of moths appear to have developed on C₃ plants in overwintering generation of ACB,and the proportion of first generation adults is 51.25%,All of the samples of second generation adults are from C₄ plants in Wenshang of Shandong;There are significant differences about the C₃ plants origins of overwintering?or first generation?adults between different geographic populations?P<0.001?,and the proportion of C₃ plants in Changtu and Yuanyang are higher than that of other regions.In Yuanyang,Chabuchar,Gongzhuling and Taonan,the proportions of overwintering generation adults from C₃ host plants were higher than that of first generation adults?P<0.05?,In Wenshang and Changtu,the proportion of first generation of ACB feeding on C₃ plants were significantly higher than other generation?P<0.001?.In the year of 2016,the average number of C₃ host plants for overwintering,first generation and second generation ACB adults in different regions was 5.06%,4.52%and 1.91%,respectively.The proportion of overwintering generation of ACB feeding on C₃ plant ranged from 0 to 25.25%in Northwest Inland Corn Region,Northern Spring Sowing Corn Region and Huang-Huai-Hai Summer Corn Region.And,the proportion of first generation?second generation?of ACB feeding on C₃ plant ranged from 0 to13.98%?0³%?in the Huang-Huai-Hai region;There are significant differences about the host sources of C₃ plants of overwintering?or first generation?adults between different geographic populations?P<0.001?,and the proportion of C₃ host plants in Shule,Chabuchar and Yuanyang are higer than that of other regions;In Chabuchar and Yuanyang,the proportions of overwintering generation of ACB feeding on C₃ host plants were higher than that of other generations?P=0.006,P<0.05?,In Harqin Banner and Zhangqiu,the sources of C₃ plants of the ACB adults were significantly higher than those in other generations?P=0.001,P<0.05?.In 2017,the average number of C₃ host plants of overwintering,first generation and second generation ACB adults in different regions was 7.05%,3.85%and 6.24%respectively.In the Northwest Inland Corn Region,the proportion of overwintering generation of ACB feeding on C₃ plant ranged from 0 to 5.56%,the proportion of first generation of ACB feeding on C₃ plant are 5.60%and 5.76%;In the Northern Spring Sowing Corn Region,the proportion of overwintering generation of ACB feeding on C₃ plant ranged from 0.48%to 4.72%,the proportion of first generation of ACB feeding on C₃ plants are less than 2.66%;There are significant differences about the host sources of C₃ plants of overwintering?or first generation?adults between different geographic populations?P<0.001,P<0.001?.In Yuanyang and Wenshang,the proportion of C₃ host plants are higher than that of other regions.In Gongzhuling,Yuanyang and Wafangdian,The C₃ host plants of overwintering are higher than other generations?P=0.017,P<0.001,P=0.014?,and in the New city district of Urumchi,the C₃ plants of first generation were significantly higher than the overwintering generation?P=0.008?.