DISCRIMINATION BY THE PUPAL PARASITE MUSCIDIFURAX ZARAPTOR1 FOR LIVE AND FREEZE-KILLED HOUSE FLY2 PUPAE3

Abstract

Muscidifurax zaraptor Kogan and Legner was able to discriminate between live and freeze-killed house fly pupae at low parasite-to-host ratios (1:40) and preferred live hosts. As the parasite-host ratio and resulting rates of parasitism increased, a greater preference was shown for live hosts. However, high parasite-host ratios (1:5) where levels of parasitism reached the upper limits in live hosts (65 – 70%), discrimination disappeared suggesting that less suitable freeze-killed hosts were selected as hosts over previously stung but unparasitized live hosts. Freeze-killed house fly pupae may be useful in measuring natural Muscidifurax activity especially during periods of low natural host populations and may provide a ready host source in conjunction with parasite releases.