THE MOOSE FLY, HAEMATOBOSCA ALCIS (MUSCIDAE) AND SKIN LESIONS ON ALCES ALCES

Large numbers of the moose fly, Haematobosca alcis (Snow, 1981), were present on the rump and posterior aspect of the hind legs of a captive, 3-year-old female moose from mid-May to early September. Few were collected off a calf moose or woodland caribou housed nearby. Sweep-net collections over the rump of the moose at 0900 hr contained equal numbers of males and females; females predominated in collections at 1600 hr. Open skin lesions first appeared in mid-June on the female moose in the poster-lateral region of both hind legs about 10-18 cm above the tibio-tarsal joint (the hock). Throughout July and August, up to twelve spherical, wet, pinkish wounds were present on each hind leg. Individual lesions were up to 1.5 cm in diameter, while some coalesced from forming larger lesions. Persistent skin lesions resulted from clusters of H. alcis feeding, possibly at the site of bite wounds made initially by the larger tabanid flies. The wounds were enlarged over summer by moose flies feeding or drinking at the periphery and were prevented from healing until September when fly numbers declined