TRAPPING SHEEP BLOWFLIES WITH LURES BASED ON BACTERIAL CULTURES

Baits of Proteus mirabilis cultured in a commercial medium or in a gut mucus mixture were tested in New Zealand sheep pasture for their abil ity to trap sheep strike flies. Liver-sodium sulfide baits were used f or comparison. At the start of the flystrike season, medium cultures w ere as effective as liver-sodium sulfide baits in trapping flies. As t he season progressed, the liver-sodium sulfide mixture trapped a signi ficantly higher number of Lucilia cuprina and Calliphora stygia than m edium cultures, though they trapped significantly fewer Chrysomya rufi facies. 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 b acterial odours in the field.