HORN FLY (DIPTERA, MUSCIDAE) CONTROL AND WEIGHT GAINS OF YEARLING BEEF-CATTLE

Horn fly, Haematobia irritans (L.), populations were controlled on yea rling cattle (n = 246) during the glazing season at moderate levels (6 8% control) with th; use of organophosphate- and pyrethyroid-impregnat ed ear tags. Weight gains of treated cattle during the 3-yr period wer e 17% greater than for untreated cattle. Results from this study demon strated that yearling cattle of 25 or 50% Brahman, Bos indicus, breedi ng responded with improved animal performance in Louisiana when modera te horn fly control was achieved.