Entomologia Experimentalis et Applicata (2008) 127, 118-124

Devon L. Francke, Jason P. Harmon, Chad T. Harvey and Anthony R. Ives (2008)
Pea aphid dropping behavior diminishes foraging efficiency of a predatory ladybeetle
Entomologia Experimentalis et Applicata 127 (2), 118-124
Abstract: Antipredator defensive behaviors are a well-studied and often crucial part of prey life histories, but little has been done to quantify how such behaviors affect natural enemies, their foraging, and their effectiveness as biological control agents. We explored how the generalist predatory coccinellid Harmonia axyridis Pallas (Coleoptera: Coccinellidae) affects the dropping behavior of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), and in turn, how that defensive behavior affects the foraging efficiency of the predator. Experimental arenas that allowed or prevented pea aphid dropping were compared to determine how dropping influences the foraging of multiple life stages of H. axyridis: second instars, fourth instars, and adults. Dropping reduced predation on aphids by all ladybeetle life stages. Despite older predators inducing more dropping, aphid dropping reduced predation by approximately 40% across all ladybeetle life stages. Aphid dropping and predator consumption of aphids were both correlated with how much the predator moved, which also increased with predator life stage. We suggest that the high rates of dropping induced by H. axyridis and the subsequent decrease in H. axyridis foraging efficiency may partially explain why H. axyridis is less effective at controlling pea aphids than it is at controlling other aphid species that do not drop.
(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): Jason P. Harmon, Chad T. Harvey, Anthony R. Ives

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Acyrthosiphon pisum
Harmonia axyridis (predator)	Acyrthosiphon pisum