Systemic insecticide study on livestock in California, 1967-68. 2. Evaluation of Imidan for cattle grub control.

Abstract

Comparative evaluation data for grub control are presented chiefly on Imidan® (O,O-dimethyl S-phthalimidomethyl phosphorodithioate) and crufomate and in 1 test only on fenthion and trichlorfon. These animal systemics were tested on 4852 indigenous cattle in 7 regions of northern California. Of this number, 2909 cattle in 5 regions were available for evaluation of grub control. Grub reduction, following pour-on applications, averaged 98.3, 92, and 96.2% with dosages of Imidan at 26, 20, and 13 mg/kg, respectively, and 95.1% with crufomate at 37 mg/kg. Pour-on applications of Imidan (26 mg/kg) gave 100% grub reduction compared to those of 98% with fenthion (7.5 mg/kg) and 94% with trichlorfon (25 mg/kg). Early season spray applications resulted in mean grub reductions of 96.5 and 97.7% for WP and EC formulations of Imidan, respectively. Grub reductions were 99-100% for Imidan and 99% for crufomate following spray applications in I test herd. In late December, lmidan showed poor or no grub reduction from spray applications, but 99-100% emcacy from pour-on treatments. The common cattle grub Hypoderma lineatum (de Villers), was more common than the nonhern cattle grub. H. bovis(L..), during evaluation for grub control and was the only species found in 4 of 13 herds examined. Mild side effects occurred in 22 lmidan-treated calves of 4852 callie tested with various animal systemics. The factor of early seasolt grub treatments was considered important in avoiding a greater incidence of adverse reactions in cattle, since 80% were treated from july through September.