Environmental Effects Upon Reproduction of a Mushroom-infesting Cecid Fly, Mycophila speyeri (Barnes) (Diptera: Ceciodomyiidae)

Abstract

AbstractMycophila speyeri Barnes is presently the most important mushroom-infesting cecid fly in Pennsylvania. Larval paedogenesis is the main means of reproduction (used by this species). Adult cecid fiies and sexual reproduction arc rarely observed in mushroom growing houses. The higher temperatures of spawn-run (70 ° to 75 °F.) are very favorable to paedogenetic reproduction of M. speyeri. Under these conditions, a generation is completed in about one week and about ten daughter-larvae per mother-larva are produced. The quantity of malt in the culture medium, the age of the spawn, and strain differences in spawn also play roles in the length of a generation and the number of young produced by a mother-larva. The lower temperatures (55 ° to 60 °F.), normal during mushroom cropping, approximately triple the time required to complete a generation. Prevention of cecid infestations during the spawn-run and sanitation to prevent spread, once larvae are present, are important considerations in the control of M. speyeri. Adult cecid flies occur only when populations become crowded on old growing media.