Control of German Cockroaches Aboard U. S. Naval Surface Ships on the East Coast12

Residual deposits of diazinon, Dursban® (O, O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate), propoxur, and malathion were applied on board U. S. Naval ships for control of Blattella germanica (L.). Diazinon failed to give acceptable control on 4 out of 5 ships. Dursban at 0.25% gave poor control when applied to 2 ships, but when the concentration was increased to 0.5%, excellent control was achieved on 6 ships and good control on the seventh. Residues of propoxur gave excellent control of cockroaches on 3 ships, poor control on 4 others, and another had too few cockroaches to evaluate. Residual deposits of 2.0% malathion resulted in poor control.