Outdoor Rearing Technique for Mass Production of Onion Maggots (Diptera: Anthomyiidae)

Abstract

We conducted experiments to determine the feasibility of producing large numbers of Delia antique (Meigen) using outdoor larval rearing beds. Eggs collected from ca. 100,000 to 200,000 adults in the laboratory from mid-September to early October were used to infest beds filled with sliced onions “planted” in brick sand. With supplemental heating available if required, larvae pupated by the end of November. Pupae in diapause were left in the beds over winter, were washed out of the sand in early April, and were then placed in cold storage where they could be stored for up to 1 year. The technique proved suitable for production of as many as 50,000 pupae per m2 of bed. Requirements for ca. 1,000,000 pupae per year were met, with insect quality at least as good as that of insects produced in laboratory rearing programs, and with substantially lower production costs.