Journal of Chemical Ecology (2012) 38, 340-347

Christina M. Harris, John R. Ruberson, Robert Meagher and James H. Tumlinson (2012)
Host suitability affects odor association in Cotesia marginiventris: Implications in generalist parasitoid host-finding
Journal of Chemical Ecology 38 (4), 340-347
Abstract: Insect herbivores often induce plant volatile compounds that can attract natural enemies. Cotesia marginiventris (Hymenoptera: Braconidae) is a generalist parasitoid wasp of noctuid caterpillars and is highly attracted to Spodoptera exigua-induced plant volatiles. The plasticity of C. marginiventris associative learning to volatile blends of various stimuli, such as host presence, also has been shown, but little is known about how this generalist parasitoid distinguishes between host species of varying suitability. Spodoptera exigua is an excellent host that yields high parasitoid emergence, while Trichoplusia ni serves as a sub-optimal host species due to high pre-imaginal wasp mortality. We have found that S. exigua and T. ni induce different volatile blends while feeding on cotton. Here, wind tunnel flight assays were used to determine the importance of differentially induced volatiles in host-finding by C. marginiventris. We found that, while this generalist parasitoid wasp can distinguish between the two discrete volatile blends when presented concurrently, a positive oviposition experience on the preferred host species (S. exigua) is more important than host-specific volatile cues in eliciting flight behavior towards plants damaged by either host species. Furthermore, wasps with oviposition experience on both host species did not exhibit a deterioration in positive flight behavior, suggesting that oviposition in the sub-optimal host species (T. ni) does not cause aversive odor association.
(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): James H. Tumlinson, John Ruberson, Robert L. Meagher

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.
	Spodoptera exigua
Cotesia marginiventris (parasitoid)	Spodoptera exigua