E-β-farnesene synergizes the influence of an insecticide to improve control of cabbage aphids in China

Extensive use of pesticides to control insect pests can have negative effects on the environment, natural enemies and food safety. The aphid alarm pheromone, E-beta-farnesene (E beta f), appears to hold strong potential for controlling a wide variety of aphid pests. To understand the control potential of E beta f, we used field experiments in a factorial design to test its influence and that of the insecticide imidacloprid on populations of aphids Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer) on Chinese cabbage, Brassica rapa pekinensis (Brassicales: Brassicaceae). Our results showed imidacloprid treatment alone can significantly decrease aphid populations, and that combining insecticide with E beta f further reduced numbers of apterous aphids at distances of 5 m from pheromone emitters in two years of our experiments. Our results demonstrate that imidacloprid can be effective in reducing the abundance of aphids in Chinese cabbage fields, but the degree of control can be even stronger in the presence of E beta f. (C) 2012 Elsevier Ltd. All rights reserved.