Environmental Entomology (1993) 22, 770-775

I.V. MacRae and B.A. Croft (1993)
Influence of temperature on interspecific predation and cannibalism by Metaseiulus occidentalis and Typhlodromus pyri (Acarina: Phytoseiidae)
Environmental Entomology 22 (4), 770-775
Abstract: Interspecific predation and cannibalism and associated rates of oviposition were assessed for adult female Metaseiulus occidentalis (Nesbitt) and Typhlodromus pyri Scheuten when provided nonlimiting amounts of either eggs, larvae, protonymphs, or deutonymphs. Tests with all four stages of phytoseiids and larvae of Tetranychus urticae Koch were carried out at 25°C:. At 15 and 12.5°C, only larvae of phytoseiids and larvae of T. urticae were prey items. Predation by T. pyri was higher than by M. occidentalis at 12.5 and 15°C but more similar at 25°C. M. occidentalis did not feed appreciably on phytoseiid larvae at 15 and 12.5°C. Neither phytoseiid oviposited at 12.5°C when fed phytoseiid larvae, but T. pyri did at 15°C:. We concluded that T. pyri was a more active predator at low temperatures. Early-season predation on M. occidentalis immatures by T. pyri could contribute to displacement of M. occidentalis from apple orchards in western Oregon.
(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:
environment/habitat manipulation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tetranychus urticae	Apple (Malus)	U.S.A. (NW)
Galendromus occidentalis (predator)	Tetranychus urticae	Apple (Malus)	U.S.A. (NW)
Typhlodromus pyri (predator)	Tetranychus urticae	Apple (Malus)	U.S.A. (NW)