Abstract
BACKGROUND: Two important pests of the sweet pepper, Capsicum annuum, are the peach potato aphid, Myzus persicae, and
the glasshouse potato aphid, Aulacorthum solani. Current aphid control measures include the use of biological control agents,
i.e. parasitic wasps, but with varying levels of success. One option to increase parasitoid efficiency is to activate plant defence.
Therefore, sweet pepper plants were treated with the naturally occurring plant defence activator cis-jasmone, and its impact
upon the behaviour and development of aphids and aphid parasitoids was investigated.
RESULTS: Growth rate studies revealed that the intrinsic rate of population increase of A. solani and M. persicae on sweet pepper
plants treated with cis-jasmone (cJSP) was not affected compared with untreated plants (UnSP), but the positive behavioural
response of alate M. persicae towards the volatile organic compounds (VOCs) from UnSP was eliminated by cis-jasmone
treatment 48 h previously (cJSP48). In addition, the aphid parasitoid Aphidius ervi preferred VOCs from cJSP48 compared with
UnSP, and a significant increase in foraging time was also observed on cJSP. Analysis of VOCs collected from cJSP48 revealed
differences compared with UnSP.