Electroantennogram and behavioural responses of two varieties of Leis axyridis from three types of habitats to aphid-damaged tea shoot volatiles and aphid kairomones
不同生境异色瓢虫对茶梢互利素和蚜虫利它素EAG和行为反应

Electroantennogram (EAG) and behavioural responses show that the tea shoots damaged by tea aphid,Toxoptera aurantii,emit synomones capable of seducing tea aphid's natural enemies,Leis axyridis (Pallas) var.spectabilis Faldermaenn and Leis axyridis (Pallas) ab.conspicua Faldermaenn.Hexane or ether rinses of body surface of T.aurantii and mustard aphid,Lipaphis erysimi and honeydew of T.aurantii contain kairomones luring the two varieties of the ladybug,in which a few specific components are proved to be more attractive than the other ones.The synomones and the kairomones derived from tea,mulberry and vegetable gardens are especially stimulative to ladybugs from the respective habitats,demonstrating the habitat specificity of EAG and behavioural responses of the ladybugs.EAG dose-responses suggest that L.axyridis (Pallas) var.spectabilis Faldermaenn is a little more sensitive to semiochemicals than L.axyridis (Pallas) ab.conspicua Faldermaenn,probably for there are chemical sensors on the antennae of the former than the later.