七星瓢虫与异色瓢虫对烟蚜的捕食功能反应及寻找效应

目的]了解不同龄期七星瓢虫与异色瓢虫对烟蚜的控制作用。方法]研究不同龄期七星瓢虫与异色瓢虫对烟蚜的捕食功能反应及寻找效应。结果]2种瓢虫的日均实际捕食量随着蚜虫密度的增大而增大。从龄期看,在烟蚜密度相同时,七星瓢虫与异色瓢虫均为成虫对烟蚜的捕食量最大,其次依次为4龄幼虫、3龄幼虫、2龄幼虫、1龄幼虫。通过比较功能反应中的各参数可知,2种瓢虫对烟蚜的攻击率随着龄期的增加而提高,七星瓢虫对烟蚜的攻击率从1龄幼虫的0.562 0增加到成虫的1.174 1,异色瓢虫对烟蚜的攻击率从1龄幼虫的0.595 1增加到成虫的1.170 5;2种瓢虫相比,幼虫时期,七星瓢虫对烟蚜的攻击率小于异色瓢虫,而成虫则相反。七星瓢虫与异色瓢虫对烟蚜的寻找效应是随着猎物的增加而降低。结论]试验结果为烟蚜的综合防治提供了理论依据。

Predation Function Response and Searching Ratio of Coccinella septempunctata and Harmonia axyridis to Myzus persicae

Objective] The aim was to study the control action of different ages of Coccinella septempunctata and Harmonia axyridis to Myzus per-sicae.Method] The predation effect of the two kinds of ladybirds,Coccinella septempunctata and Harmonia axyridis,on Myzus persicae were ob-served in laboratory. Result] Much more aphids were preyed by the two ladybirds when the density of the aphid was high.When the prey density was same,adults of the two ladybirds preyed the largest amount of aphids,followed by the 4th-instar larvae,3th-instar larvae,2nd-instar larvae and 1st-instar larvae.Attact rate against the aphid raised with the development of the ladybird.Attact rate of C.septempunctata raised from 0.5620 in 1st-instar larvae to 1.1741 in adult and attact rate of H.axyridis raised from 0.5951 in 1st-instar larvae to 1.1705 in adult.Attact rates of C. septempunctata was slower than these of H.axyridis in larvae,but inverse in adults.Searching ratio of C.septempunctata and H.axyridis reduced with the decrease of aphid density.Conclusion] The results provide reference for the comprehensive control of Myzus persicae.