CO-RAL SPRAYS FOR SYSTEMIC CONTROL OF THE CATTLE GRUBS HYPODERMIC BOVIS L. AND H. LINEATUM DE VILL.

Abstract

Aqueous suspensions of 0.25, 0.5, and 0.75 per cent (weight on volume) of CO-RAL in wettable powder were sprayed on Hereford calves for the control of prehypodermic cattle grubs. Two types of CO-RAL sprays were used, one with anionic and the other with a combination of anionic and non-ionic surfactants. They were applied at pressures of 50 and 400 lb. per square inch, and when the lower pressure was used the spray gun was equipped with a hair rake to ruffle the hair. One gal. of spray per head was applied once to the backs and sides of each calf. Sprays containing 0.75 per cent CO-RAL reduced the number of grubs in treated calves by 86 and 90 per cent (P > 0.01) as compared with the number in the untreated group. There was no difference in larvicidal effects between 0.25 and 0.5 per cent sprays, both of which reduced the number of grubs by 60 to 70 per cent. Neither the surfactants used nor the pressures employed had any effect on larvicidal properties of CO-RAL sprays.None of the treated calves showed signs of organophosphorous poisoning, but an outbreak of shipping fever was noticed in the herd. Question is raised if the stress of CO-RAL sprays, which are cholinergic in effect, lowered the resistance of the treated calves to shipping fever, against which they had been vaccinated previously.

DISTRIBUTION OF CHOLINESTERASE IN THE LARVAE OF HYPODERMA BOVIS AND HYPODERMA LINEATUM (DIPTERA: OESTRIDAE) AND ITS INHIBITION BY SYSTEMIC INSECTICIDES

“…Three such insecticides are coumaphos (Co-Ral) ,' trichlorfon (Dipterex, Neguvon) ," and Ruelene." Coumaphos has been favourably reported on by Smith and Richards (1954), Brundrett, McGregor, and Bushland (1957), and Khan, Thompson, and Pelham (1959). Trichlorfon was tested by Drummond and ihfoore (1960) and Drummond (1963).…”