Sublethal Effects and Mortality of Tabanids (Diptera: Tabanidae) Induced by Fenvalerate Treatment of Cattle

The effect of fenvalerate spray treatments of cattle upon the feeding success and survival of tabanids was examined. There was a reduction in feeding time for tabanids feeding on treated cows ranging from 27.4 to 38.8%. There was also a 31% reduction in engorgement weight of Tabanus fuscicostatus Hine. The time that flies were allowed to feed upon fenvalerate-treated steers had no significant effect upon mortality rates or knockdown percentages.