Environmental Entomology (1983) 12, 429-433

M.P. Parrella and R.L. Horsburgh (1983)
Functional responses of the black hunter thrips, Leptothrips mali (Thysanoptera: Phlaeothripidae), to densities of Panonychus ulmi (Acari: Tetranychidae)
Environmental Entomology 12 (2), 429-433
Abstract: The functional responses of all feeding stages of Leptothrips mali (Fitch) to various densities of selected Panonychus ulmi (Koch) stages were determined in the laboratory at 23.9 ± 1°C. Functional response data were obtained for the following L. mali - P. ulmi combinations: first-stage larvae of L. mali with P. ulmi eggs and adults, second-stage larvae or adult female L. mali with adult P. ulmi. To estimate the relationship between the number of prey killed and prey density for the selected predator-prey combinations, various mathematical models were fit to the data. No functional response was found when first-stage larvae were provided adult female P. ulmi. A sigmoid curve best explained the relationship in all other situations. Search rate increased between the two lowest prey densities when adult thrips were provided adult mites. No such increase was observed with other L. mali - P. ulmi combinations; search rate remained constant. Therefore, for these other stages, the type III response obtained cannot be explained on the basis that the search rate increases over an initial range of low prey densities. A possible explanation may be interference-stimulation of the predator by the prey above some threshold prey density.
(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:
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.
	Panonychus ulmi
Leptothrips mali (predator)	Panonychus ulmi