Variation in populations of mine- and gall-forming Diptera and the growth form of their host plant, bracken (Pteridium aquilinum (L.) Kuhn)

Abstract

Eight species of Diptera belonging to the families Anthomyiidae, Cecidomyiidae and Agromyzidae utilize bracken in different ways and show preferences for different types of bracken habitat. The annual and local variation found in populations of these mining and gall-forming herbivores in different sites in Southeast England over a four-year period are described. Possible reasons for the differences in distribution patterns are discussed, in terms of the growth and phenology of the host plant, resource availability and natural enemies.