Journal of Chemical Ecology (2001) 27, 33-43

S. Al Abassi, M.A. Birkett, J. Pettersson, J.A. Pickett, L.J. Wadhams and C.M. Woodcock (2001)
Response of the ladybird parasitoid Dinocampus coccinellae to toxic alkaloids from the seven-spot ladybird, Coccinella septempunctata
Journal of Chemical Ecology 27 (1), 33-43
Abstract: Electrophysiological and behavioral responses of the ladybird parasitoid Dinocampus coccinellae to volatiles from the seven-spot ladybird, Coccinella septempunctata, were investigated to identify semiochemicals involved in host location. Coupled gas chromatography-electroantennography (GC-EAG) with D. coccinellae located a small peak of prominent activity in an extract of volatiles from adult C. septempunctata. The active compound was identified by coupled GC-mass spectrometry and by comparison with an authentic sample as the free-base alkaloid precoccinelline, which forms part of the toxic defense of this ladybird. Behavioral studies in an olfactometer showed that D. coccinellae was significantly attracted to the volatile extract and also to the alkaloid. Myrrhine, a stereoisomer of precoccinelline found in low amounts in C. septempunctata and in other ladybird species, was shown to be electrophysiologically active and significantly attractive. Perception of ladybird alkaloids by D. coccinellae is a rare example of toxicants acting as aerially transmitted cues for interactions between the third and fourth trophic levels.
(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, Michael A. Birkett

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Coccinella septempunctata (predator)