Interspecific predation and cannibalism and associated rates of oviposition were assessed for adult femaleMetaseiulus occidentalis(Nesbitt) andTyphlodromus pyriScheuten when provided nonlimiting amounts of either eggs, larvae, protonymphs, or deutonymphs. Tests with all four stages of phytoseiids and larvae ofTetranychus urticaeKoch were carried out at 25°C. At 15 and 12.5°C, only larvae of phytoseiids and larvae ofT. urticaewere prey items. Predation byT. pyriwas higher than byM. occidentalisat 12.5 and 15°C but more similar at 25°C.M. occidentalisdid not feed appreciably on phytoseiid larvae at 15 and 12.5°C. Neither phytoseiid oviposited at 12.5°C when fed phytoseiid larvae, butT. pyridid at 15°C. We concluded thatT. pyriwas a more active predator at low temperatures. Early-season predation onM. occidentalisimmatures byT. pyricould contribute to displacement ofM. occidentalisfrom apple orchards in western Oregon.