ECONOMIC-EFFECTS OF HORN FLY (DIPTERA, MUSCIDAE) POPULATIONS ON BEEF-CATTLE EXPOSED TO 3 PESTICIDE TREATMENT REGIMES

Horn flies could not be maintained below 50 per animal with sprays or dusts during a 21-wk study. However, weights of cows and calves and condition scores of cows were not influenced by suppression of Haematobia irritans (L.) populations. Results show that cattle in northwest Florida can tolerate average populations of greater-than-or-equal-to 200 flies for 70 d with no adverse economic effects. Spray treatments providing the best fly control were Lintox-D and Ra-Vap. The most economical products for use were Del-Tox, Lintox-D, and Ra-Vap.