How to Manage Pests

Pests in Gardens and Landscapes

Parasitic wasps

The parasite Aphelinus mali can completely control aerial colonies of the woolly apple aphid. Populations of this parasite often increase rapidly in fall after the effects of summer spraying have diminished. When monitoring aphids, examine the colonies to determine the level of parasitization; parasitized aphids are black and may have an exit hole from which a parasite emerged.

Blackened aphid bodies are parasitized
Blackened aphid bodies are parasitized


Statewide IPM Program, Agriculture and Natural Resources, University of California
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