Environmental Entomology (1989) 18, 892-896

David H. Oi and Martin M. Barnes (1989)
Predation by the western predatory mite (Acari: Phytoseiidae) on the Pacific spider mite (Acari: Tetranychidae) in the presence of road dust
Environmental Entomology 18 (5), 892-896
Abstract: Laboratory and greenhouse studies examined the effects of road dust on predation by the western predatory mite; Typhlodromus (=Galandrornus) occidentalis (Nesbitt), on the Pacific spider mite, Tetranychus pacificus McGregor. Significantly fewer Pacific spider mites were found on bean plants and almond trees with western predatory mites regardless of the presence or absence of dust. A detrimental effect of dust was not evident on populations of western predatory mites. The effect of dust on populations of Pacific spider mites was not conclusive because high and low populations were associated with the presence of dust. In addition to dust and predators, we examined the effect of almond tree water stress on predation. Water stress did not have any significant effects on either population, however the accumulated degree hour difference between stressed and nonstressed trees was low. These studies suggest that road dust does not influence predation by western predatory mites on Pacific spider mites.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): David H. Oi

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
environment - cropping system/rotation
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tetranychus pacificus	Almond (Prunus dulcis)
	Tetranychus pacificus	Beans (Phaseolus)
Galendromus occidentalis (predator)	Tetranychus pacificus	Almond (Prunus dulcis)
Galendromus occidentalis (predator)	Tetranychus pacificus	Beans (Phaseolus)