| Popis: |
Herds of cattle ranging from 15 to 80 head were tested in 2 locations in Missouri during 1979. In Boone Co., 2 herds were treated by placing a single 8.0% wt/wt Ectrin (fenvalerate) plastic ear tag per head on June 7 and 11, respectively. A herd of 70 was treated on June 6 at the rate of 2 tags/head with Shoo-Fly wick-type ear devices containing 1.0% dichlorvos in heavy gear oil. Additional herds were sprayed to run-off with the following materials on dates indicated using a power sprayer delivering 150 Ib/sq in (1034 kPa): 0.06% Co-Ral WP (June 16, July 14, and August 31), 0.5% Rabon WP (June 20, July 10, August 11, and September 17), 0.5% Ravap EC (May 31, June 12, July 10, August 11, and September 17), and 0.5% toxaphene EC (2 herds: the 1st on dates identical with the Ravap treatments, and the 2nd on June 20, July 10, August 17, and September 18). Untreated control herds were maintained in 2 locations; however, the 1st of these was treated with Insecticide during mid-season. Similar tests were conducted in Linn Co., where separate herds were treated with 1 or 2 Ectrin tags/head on May 4. On June 21, an additional herd was treated at the rate of 2 tags/head with Shoo-Fly devices containing 1.25% Revap in heavy gear oil. Topical sprays were applied In a manner identical to that used in Boone Co. One herd was treated with 0.5% toxaphene on June 1, June 14, and July 3; 2 herds were sprayed with 0.5% Ravap on these dates. A similar, untreated control herd was maintained in a proximate location. In all cases assessment of treatment efficacy was made on a weekly basis via Inspection of 10 head selected at random from each herd. Face flies were counted on the entire face, and horn flies on a single side of each animal examined. Data thus obtained was converted to logjQ (n+1) prior to analysis; however, true averages are reported. |
