Evaluation of some insecticides for control of potato tubermoth, phthorimaea operculella (Zeller)*

Field trials were conducted for evaluating the comparative efficacy of four insecticides against potato tubermoth, Phthorimaea aperculella (Zell.) in three rabi seasons (1977 to 1980) at Central Potato Research Station, Rajgurunagar. The results indicate that these insecticides viz; methamidophos, monocrotophos, phosalone and quinalphos @ 0.90, 0.60. 0.525 and 0.375 kg (a.i.) per hectare, respectively, are effective in reducing plant damage, larval population, tuber damage and increasing the yield of healthy tubers. These insecticides should be applied at 1st appearance of the pest and the treatment may be repeated at fortnightly intervals depending upon persistance of infestation. About four sprayings are required to protect the crop from tubermoth damage.