Trapping sheep blowflies with lures based on bacterial cultures

Abstract

Summary. Baits of Proteus mirabilis cultured in a commercial medium or in a gut mucus mixture were tested in New Zealand sheep pasture for their ability to trap sheep strike flies. Liver–sodium sulfide baits were used for comparison. At the start of the flystrike season, medium cultures were as effective as liver–sodium sulfide baits in trapping flies. As the season progressed, the liver–sodium sulfide mixture trapped a significantly higher number of Lucilia cuprina and Calliphora stygia than medium cultures, though they trapped significantly fewer Chrysomya rufifacies.

In one case the medium culture trapped a significantly higher proportion of gravid L. cuprina than the liver–sodium sulfide mixture. Adding dimethyl sulfoxide to the medium culture significantly reduced its efficacy.

The gut mucus culture was significantly less effective than the liver–sodium sulfide bait in trapping gravid L. cuprina, and significantly more effective in trapping Chrysomya rufifacies. This is the first published record of sheep strike flies being attracted by bacterial odours in the field.