Investigations in the control of the tobacco leaf-miner, Gnorimoschema operculella Zell. (Lepitoptera: Gelechiidae), with D.D.T. and "Gammexane"

Abstract

Experiments in the control of the tobacco leaf-miner, Gnorimoschema operculella Zell., with D.D.T. and "Gammexane" were conducted at Mereeba in northern Queensland. Effective control was obtained with 0.1 per cent D.D.T. sprays and 1.0 and 2.0 per cent D.D.T. dusts applied immediately after transplanting, followed by regular fortnightly treatments up to a maximum of five applications in all. A total of three applications made at fortnightly intervals also afforded a high degree of protection to the crop. "Gammexane" at the high concentration was inferior to D.D.T. even at the low concentration of the latter; in addition, the sprays and dusts containing it had such a pronounced phytocidal effect on the tobacco plants that their use had to be discontinued before the termination of the experiment.