Candidate Concentrate Formulations for Control of Flies on Horses, 1991

Abstract

Abstract Twelve thoroughbred mares (18 to 22-yrold) were randomly assigned to 3 treatment groups (3 mares per group) and a control (untreated) group. Experimental preparations were applied to one side of the horses in a 0.5 m2 area using a manual mist sprayer until wet to the skin. Fifty stable flies (2 to 4-d-old) and 25 house flies (2 to 4-d-old) were placed in separate tea strainers (12.7 cm diam) and fed 10% sugar water on a cotton pad 24 h prior to exposure. One strainer containing stable flies and another containing house flies were positioned on the treated areas of each animal and held in place with elastic straps for 15 min at —Id, 0, 1, 3, and 6 h, and daily through 14 d. After exposure, flies were anesthetized with COa and 25 individuals of each species were transferred to clean paper cages (473 ml) with screen tops for mortality studies. House flies were provided with 10% sugar water and stable flies with citrated porcine blood. Mortality was determined at 24-h postexposure. The remaining 25 stable flies were tested for blood meal acquisition by squashing them on a paper towel. Temperature and relative humidity ranged from 1-28°C and 83-100%, respectively. The only precipitation was 5.1 cm on d 9 of the test. Data were subjected to analysis of variance (ANOVA) and means separated using Fisher's protected least significant difference test. Difference among means were considered significant at P < 0.05.