Tests with Dow ET-57 against Cattle Grubs in Oregon1

Abstract
During 1955-56 Dow ET-57 was tested as a systemic against cattle grubs (Hypoderma lineatum) and bovis at doses of 10 to 200 mg/kg. This material was effective against grubs present in the backs of animals as well as against the encystment of new ones. Second-instar grubs were killed more rapidly and efficiently than 3d-instar grubs. The material failed to kill many of the grubs that were within 2 weeks of emergence. In limited spray tests the material caused 100% kill of grubs at 2.5 but only about 50% or less at 1% concentration.