Activation of defence in sweet pepper, Capsicum annum, by cis-jasmone, and its impact on aphid and aphid parasitoid behaviour.
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.


CONCLUSIONS
There is evidence that treatment with cis-jasmone has the potential to improve protection of sweet pepper against insect pests.
Biological Chemistry Department, Rothamsted Research, Harpenden, Herts, UK. sarah.dewhirst@rothamsted.ac.uk
Sarah Y
SY
Dewhirst
Michael A
MA
Birkett
Elisa
E
Loza-Reyes
Janet L
JL
Martin
Barry J
BJ
Pye
Lesley E
LE
Smart
Jim
J
Hardie
John A
JA
Pickett
D000818:Animals; D001042:Aphids / Q000469:parasitology / Q000502:physiology*; D002212:Capsicum / Q000187:drug effects* / Q000276:immunology* / Q000469:parasitology; D003517:Cyclopentanes / Q000494:pharmacology*; D054883:Oxylipins / Q000494:pharmacology*; D010572:Pest Control, Biological / Q000379:methods*; D055549:Volatile Organic Compounds / Q000276:immunology; D014863:Wasps / Q000502:physiology*
D003517:Cyclopentanes; D054883:Oxylipins; D055549:Volatile Organic Compounds; C086299:jasmone