COMPARATIVE TEST WITH INSECTICIDE-IMPREGNATED EAR TAGS AGAINST GULF COAST TICK (ACARI IXODIDAE)

An 8% fenvalerate (synthetic pyrethroid) impregnated ear tag was at least equal in controlling Amblyomma maculatum Koch on cattle to those containing 15% stirofos and 10% chloropyrifos, which were highly effective in extensive evaluations in previous years. The residual effect of the stirofos impregnated ear tag was adequate to protect animals'' ears from ticks for 11 wk, but when the ear tag was applied 6 wk early, it caused only marginally satisfactory control against a heavy tick population.