Journal of Chemical Ecology (1998) 24, 1355-1368

Yongjun Du, Guy M. Poppy, Wilf Powell, John A. Pickett, Lester J. Wadhams and Christine M. Woodcock (1998)
Identification of semiochemicals released during aphid feeding that attract parasitoid Aphidius ervi
Journal of Chemical Ecology 24 (8), 1355-1368
Abstract: Herbivore induced release of plant volatiles mediating the foraging behavior of the aphid parasitoid Aphidius ervi was investigated using the pea aphid, Acyrthosiphon pisum, feeding on broad bean, Vicia faba. Behavioral responses were studied using an olfactometer and a wind tunnel. Volatiles obtained by air entrainment of aphid infested plants were more attractive to A. ervi than those from uninfested plants, in both behavioral bioassays. GC-EAG of both extracts showed a number of peaks associated with responses by A. ervi, but with some differences between extracts. Compounds giving these peaks were tentatively identified by GC-MS and confirmed by comparison with authentic samples on GC, using two columns of different polarity. The activity of pure compounds was further investigated by EAG and wind tunnel assays. Results showed that, of the compounds tested, 6-methyl-5-hepten-2-one was the most attractive for A. ervi females, with linalool, (Z)-3-hexen-1-yl acetate, (E)-ß-ocimene, (Z)-3-hexen-1-ol, and (E)-ß-farnesene all eliciting significantly more oriented flight behavior than a solvent control. Foraging experience significantly increased parasitoid responses to these compounds, with the exception of (E)-ß-farnesene. Time-course GC analysis showed that feeding of A. pisum on V. faba induced or increased the release of several compounds. Release of two of these compounds (6-methyl-5-hepten-2-one and geranic acid) was not induced by the nonhost black bean aphid, Aphis fabae. During the analysis period, production of (E)-ß-ocimene remained constant, but 6-methyl-5-hepten-2-one, linalool, geranic acid, and (E)-ß-farnesene appeared during the first day after A. pisum infestation and increased in concentration with increasing time of aphid feeding.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): John A. Pickett, Guy M. Poppy

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Acyrthosiphon pisum	Broad/faba bean (Vicia faba)
Aphidius ervi (parasitoid)	Acyrthosiphon pisum	Broad/faba bean (Vicia faba)