Environmental Entomology (1993) 22, 1302-1307

B.D. Congdon, C.H. Shanks Jr. and A.L. Antonelli (1993)
Population interaction between Stethorus punctum picipes (Coleoptera: Coccinellidae) and Tetranychus urticae (Acari: Tetranychidae) in red raspberries at low predator and prey densities
Environmental Entomology 22 (6), 1302-1307
Abstract: Previous studies concluded that species in the coccinellid genus Stethorus Weise, although obligate predators of tetranychid mites, exhibit a strong numerical response only to high population densities of their prey. The study reported here was conducted to test the hypothesis that in western Washington red raspberries, Stethorus punctum picipes Casey is capable of detecting and attacking spider mite populations of very low density which are distributed in small, widely scattered patches during the early part of the growing season. In addition to using conventional leaf sampling methods, S. p. picipes interactions with prey were examined by observing their response to prey patches introduced into the field from laboratory cultures. Our results indicate that S. p. picipes is active at low prey densities, although undetected by conventional sampling methods, and is capable of locating rare, small prey patches. This finding suggests that dispersal and searching ability, rather than numerical response are the key components of this preypredator association.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
pheromones/attractants/traps
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tetranychus urticae	Raspberry/blackberry (Rubus)
Stethorus punctum (predator)	Tetranychus urticae	Raspberry/blackberry (Rubus)