Effects of host plant on the oviposition preference of Plutella xylostella ( L.) and host- selection behavior of Cotesia plutellae (Kurdjmov).
寄主植物对小菜蛾产卵选择性及菜蛾绒茧蜂寄主选择行为的影响

The ovipositional preference of the diamondback moth, Plutella xylostella (L.) between different Brassica vegetable plants and the host selection by Cotesia plutellae (Kurdjmov) between host larvae on different Brassica plants were studied. With the presence of both the Chinese cabbage, B. campestris L. ssp. pekinensis, the common cabbage, Brassica oleracea L. var. capitata, P. xylostella, moths laid three times as many eggs on the former as that on the latter plants. When C. plutellae wasps were provided with equal numbers of larvae of P. xylostella on both species of plants in one area, parasitism rate of hosts on B. campestris was almost five times that on B. oleracea. The possible effects of infochemicals from the Brassica plants on the oviposition preference of P. xylostella and on the host selection by C. plutellae were discussed.