A study of codling moth (<i>Cydia pomonella</i>) parasitism by <i>Ascogaster quadridentata</i> in a derelict apple orchard

Abstract

Ascogaster quadridentata (Hymenoptera Braconidae) is a codling moth parasitoid native to Europe and established in New Zealand following introductions from the UK in the 1930s Ascogaster quadridentata parasitises the eggs of codling moth and develops and overwinters throughout the larval period of the host finally emerging from the host larval cocoon in spring As a result of its slow development the parasitoid does not protect the fruit from larval feeding damage Codling moth larvae in overwintering cocoons concealed under bark on apple trees were collected from a derelict orchard in Upper Moutere Nelson Larvae (n117) were carefully extracted from their cocoons and introduced into rolls of corrugated cardboard to complete their development Eightyeight larvae were successfully reared and 37 of these (42) were parasitized by A quadridentata This result is similar to a limited number of other records for this parasitoid in New Zealand and indicates that A quadridentata assists in reducing high populations of codling moth in derelict orchards or wild apple trees which are the main source for codling moth infestations in nearby commercial orchards