Beef Cattle Fly Control with Diflubenzuron (Vigilante tm) Bolus, 1986

Abstract

Abstract Fifty g Vigilante boluses containing 4.9g AI diflufbenzuron were evaluated for the control of horn flies and face flies under field conditions. Herds were pastured cow/calf operations located within a 40-mile radius in central Kentucky. Control herds were similar operations located within 4 miles of the treated herds. Boluses were administered to cattle with a balling gun at a rate of 1 bolus/250 kg body weight between 1 May and 15 May. Another comparison herd was tagged with Guardian (tm) ear tags during she same period and evaluated concurrently for fly control. Herds were treated as follows: 102 steers (A) treated at a rate of 1 bolus/steer; 45 cows/calves (B) treated at rate of 1.5 bolus/cow and 0.5 bolus/calf; 55 cows and 8 calves as untreated controls (conAB); 39 heifers (C) at 1 bolus/animal; 30 cows (conC) untreated; 30 cow and 12 calves at 1.5 bolus/cow and 1 eartag/calf (D); 38 cows tagged with Guardian ear tags (T) at rate of 2 tags/cow; and 30 cows untreated (conDT). The number of horn flies and face flies were counted on 10 cattle from each herd every 2 weeks. Horn flies were counted on one side of the animal; sice flies were counted on the face and head of the same animal. Fresh manure from 5 animals of each herd was collected biweekly and bioassayed utilizing newly hatched colonized horn face and house fly larvae. Twenty-five larvae were placed in 50-100 g of feces and larval mortality calculated by counting adult (mergence. Bioassays were performed on bolused cattle only.