[Ecological functions of E-β-farnesene on aphids and their natural enemies in potato field]

As a most common component of aphid alarm pheromone, E-β-farnesene (EβF) could not only dispel aphids, but also modify some behavioral responses of their natural enemies. In order to investigate the ecological function of EβF, its influence on the population dynamics of Myzus persicae (Sulzer), Aphis gossypii (Glover), Macrosiphum euphorbiaein (Thomas) and their natural enemies was studied in potato fields. The results showed that there were significantly lower aphid abundance (2012, 2013), higher ladybird beetle abundance (2012, 2013), and higher mummified aphid abundance (2012) on potato plants in EβF treated plots (100 μL per week). The numbers of aphids at the distances of 1 m and 5 m from EβF releaser were significantly lower compared to 10 m in 2012, and the aphid number was significantly lower at the distance of 1 m compared to 5 m and 10 m in 2013. Moreover, significantly higher parasitoid and hoverfly numbers in 2012 and higher numbers of ladybird beetles in 2013 were observed in yellow traps in EβF treated plots. The results suggested that EβF could suppress aphid population growth within a certain distance in potato fields.