Abstract
Groups of gravid females of Lucilia cuprina (Wiedemann) in a 1-m3 cage flew upwind in response to sheep placed upwind of the cage. No downwind flight or other response was observed to sheep placed downwind of the fly cage. Flystruck sheep stimulated the greatest accumulation of flies on the upwind cage wall (46% of the caged flies), followed by sound wet sheep (29%) and sound dry sheep (19%). All sheep tested caused significantly more flies to accumulate on the upwind wall than did controls consisting of either no bait or a man placed upwind (14%). Struck sheep elicited significant upwind movement of flies at distances of up to 20 m; sound, dry sheep did so only up to 10 m. It was concluded that L. cuprina is able to orient from a distance in response to volatile sheep kairomones; kairomones from dry sheep are augmented by wetting or the presence of cutaneous myiasis, as indicated by an enhanced fly response. The experiments performed did not exclude a role for visual or thermal cues in blowfly orientation to sheep.