title: Natural enemies of woolly apple aphid (Hemiptera: Aphididae) in Washington State.
abstract: Woolly apple aphid, Eriosoma lanigerum (Hausmann), has become a pest of increasing importance in Washington apple orchards in the past decade. The increase in aphid outbreaks appears to be associated with changes in pesticide programs and disruption of biological control. We  sampled woolly apple aphid colonies in central Washington apple orchards for natural enemies of this pest from 2006 to 2008. The most common predators encountered were Syrphidae (Syrphus opinator Osten Sacken, Eupeodes fumipennis Thomson, and Eupeodes americanus Wiedemann);  Chrysopidae (Chrysopa nigricornis Burmeister); and Coccinellidae (Coccinella transversoguttata Brown and Hippodamia convergens Guérin-Méneville). The specialist syrphid Heringia calcarata Loew was recorded for the first time occurring in Washington  apple orchards. The only parasitoid found in aerial colonies of woolly apple aphid was Aphelinus mali Haldeman; root colonies, however, were not parasitized. Identification of important natural enemies provides a better basis for conservation biological control of this pest.
authors: Washington State University, Tree Fruit Research & Extension Center, 1100 N. Western Ave., Wenatchee, WA 98801, USA. lessandomg@gmail.com
authors: Lessando M
authors: LM
authors: Gontijo
authors: Stephen D
authors: SD
authors: Cockfield
authors: Elizabeth H
authors: EH
authors: Beers
mesh_terms: D000818:Animals; D001042:Aphids / Q000502:physiology*; D061046:Biological Control Agents; D010572:Pest Control, Biological; D011235:Predatory Behavior; D014861:Washington
chemical_list: D061046:Biological Control Agents