The relative abundance of the hymenopterous parasites attacking Metopolophium dirhodum (Walker) and Sitobion avenae (F.) (Hemiptera: Aphididae) on cereals during 1973–79 in southern England

Abstract

AbstractIn studies in southern England, the relative abundance of the hymenopterous parasites attacking Metopolophium dirhodum (Wlk.) and Sitobion avenae (F.) differed between their hosts, between years (1973–79) and on whether they were assessed using field or laboratory-reared mummies. Species of the complex of Aphidius uzbekistanicus Luzhetzki were usually the commonest parasites, especially from mummies of M. dirhodum, while Aphidius picipes (Nees) was less common and tended to attack mainly S. avenae; Toxares deltiger (Hal.) was common only in 1979. Species of hyperparasites emerged most frequently from mummies of M. dirhodum, except for Dendrocerus carpenteri (Curt.), which emerged most often from S. avenae.