OBSERVATIONS ON THE IMMATURE STAGES OF GIMNOMERA CEREA AND G. INCISURATA (DIPTERA: ANTHOMYIIDAE, SCATOPHAGINAE)

Publisher Website
Google Scholar
Abstract
G. cerea larvae feed upon the ovules and capsule of Pedicularis canadensis. Distribution of the fly coincides closely with its plant host. Adult flies are active in spring during the plant’s flowering period. Both sexes of flies are predaceous on small insects. Details of mating and oviposition behavior are elaborated. After feeding, larvae form puparia in the soil around roots of the host and undergo protracted diapause. All activities of the single generation per year are closely attuned to host plant’s cycle. Distribution of G. incisurata appears to closely follow that of its hosts. Larvae feed upon the flower parts of three species of Penstemon (hirsutus, digitalis, and calycosus). Duration of adult and larval activity periods along with behavior closely parallels G. cerea. In view of known host plant preferences in the Scatophaginae, it is suggested the way in which adaptation of Gimnomera to members of the Scrophulariaceae has been established is via the parasitic or hemiparasitic members of this plant family.