Abstract

The control of rice stem borer Tryporyza incertulas Wik. is a difficult problem, as the egg masses remain covered by dense buff-coloured hairs making insecticidal penetration impossible and the hatched out larvae soon bore into the stems and remain concealed inside the stem. Hence effective control of this internal feeder is possible only by timing applications to kill the adults before they lay eggs and by killing the freshly hatched larvae before they bore inside the plant by giving a set of two sprays for each brood, the first spray synchronising with the emergence of moths and the second one, a week after the first spray. The method of application of insecticides in standing water of rice fields poses problems in the control of stem borer. Hence studies were carried out at the Regional Research Station, Aduthurai to find out the effectiveness of modern insecticides in controlling the rice stem borer by different modes of application. The results of the experiments conducted during Sama and Thaladi scasons are presented in this paper.

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