Cornicle secretions have been reported to serve multiple functions in aphids. Of particular interest are reports that these sticky secretions serve to defend aphids against attack by predators and parasites. Dixon (1958) observed that the aphid, Microlophium evansi (Theobald) will smear its cornicle secretions on the mouthparts of the coccinellid, Adalia decempunctata (L.) allowing the aphid to escape from the temporarily immobilized predators. Edwards (1966) observed parasitoid wasps ( Aphidius ) trapped in aphid cornic1e secretions in the field.