Chemical control of the "annual bluegrass weevil," Hyperodes sp. nr. anthracinus.

Abstract

Laboratory bioassays and field-plot tests were conducted in 1968 and 1969 to find a chemical control for Hyperodes sp. nr. anthracinus (Dietz), a pest of annual bluegrass on golf courses. The most effective of 25 insecticides tested in laboratory bioassays were azinphosmethyl, Supracide® (S- ((2-methoxy-5-oxo-Δ2-1,3,4-thiadiazolin- 4-yl) methyl) O,O-dimethyl phosphorodithioate), fenthion, and Dursban® (O,O-diethyl O- (3,5,6-trichloro-2-pyridyl) phosphorothioate); the least effective were heptachlor and chlordane, In general, chlorinated hydrocarbons ranked near the bottom of the list. The systemic insecticides disulfoton, propoxur, fenthion, and Dasanit® (O,O-diethyl O-[p- (methylsulfinyl) phenyl] phosphorothioate) were applied on grass tennis courts May 3, 1968. None of the treatments satisfactorily controlled the annual bluegrass weevil, but disulfoton showed the most promise. Diazinon (14 G, 5 and 2 Ib active ingredient (AI) per acre), azinphosmethyl (22 EC, 2½ and I lb AI/acre), Supracide (14 G, 5 and 2 Ib AI/acre), disulfoton (10 G, 5 and 2 Ib AI/acre), Dursban (41 EC, 2½ and I Ib AI/acre) , and fenthion (5 G, 5 and 2 Ib AI/acre) were applied on grass tennis courts April 19 and May 19, 1969, and diazinon (14 G, 5 and 2 Ib AI/acre) was applied April 19 only. Nearly all the plots treated in April and May were conspicuously healthier than their surrounding controls, but the plots treated with diazinon in April only showed considerable damage. Dursban, 2½ lb AI/acre, gave the best control. The high rate of diazinon gave good control, while the low rate gave only fair control.