Development of Spalangia Cameroni and Muscidifurax Raptor (Hymenoptera: Pteromalidae) on Live and Freeze-Killed House Fly (Diptera: Muscidae) Pupae (Report‪)‬

House flies are a primary pest with confined livestock, particularly dairy and poultry. With the continued development of insecticide resistance and the general movement toward more sustainable management systems, including IPM, increasing numbers of producers are using biological control. On livestock and poultry facilities, augmentation of naturally-occurring pteromalid parasitoids can be helpful in managing fly populations and has become more common (McKay & Galloway 1995; Kaufman et al. 2001; Geden & Hogsette 2006). Evaluation of the effectiveness of parasitoid releases continues to rely on the use of either live sentinel muscoid pupae or collection of wild pupae as hosts of the parasitoids. There are merits to both approaches, and Kaufman et al. (2001) summarized their advantages and disadvantages. A compromise system that would allow for longer field exposures of sentinel pupae is desirable because this would combine the operational advantages of the sentinel pupae approach (repeatability, rapid location, high recovery rate) with the increased species diversity characterized by collections of wild pupae. Manipulation of muscoid pupae to increase field longevity of sentinel hosts over live pupae has received considerable attention (McKay & Galloway 1995; Floate & Spooner 2001; Gibson & Floate 2004; Geden & Hogsette 2006). In addition to surveillance, the use of killed pupae has 2 advantages to the biocontrol community. First, use of killed and stored pupae would allow commercial insectaries to stockpile hosts in anticipation of increased demands for products (Floate 2002). Second, placement of masses of killed pupal hosts in livestock facilities has been demonstrated to enhance parasitism of natively occurring and augmented parasitoids by providing an opportunity for in situ amplification of local populations (Pickens & Miller 1978; Petersen 1986).