Insecticide Tests Against the Boll Weevil and the Bollworm at Tallulah, La., in 19561

Abstract

In small-plot experiments with several insecticides applied as dusts and sprays for the control of the boll weevil (Anthonomus grandis Boh.) and the bollworm (Heliothis zea (Boddie)) conducted at Tallulah, Louisiana, during 1956, Guthion gave excellent boll weevil control in all tests at dosages from 0.25 to 0.6 pound per acre. Calcium arsenate dust, methyl parathion at 0.5 and 0.67 pound, EPN at 0.5 and 0.8 pound, and malathion at 2.05 and 3.81 pounds per acre were slightly less effective. Methyl parathion at 0.40 pound, Dipterex and Dow ET-15 at 0.5 pound, and calcium arsenate spray at 12.9 pounds per acre gave only fair control. DDT was included in most of these treatments. In one experiment endrin spray at 0.3 pound gave fair control, but endrin dust at 0.37 pound per acre was ineffective. In other experiments endrin, Thiodan, and heptachlor were ineffective at the dosages used. Endrin and combination insecticides containing DDT gave good control of the bollworm. At the dosages used Thiodan and Guthion without DDT were comparable to calcium arsenate dust for bollworm control.