నైరూప్య

Level of infestation and differential response of cotton plants to damage by the stem weevil, Pempherulus affinis

S.Mohan, P.Pretheep-Kumar, M.Sivakumar, N.Balakrishnan, R.Ravikesavan

Histopathological studies carried out with the stemtissues of cotton plants of different age helped to trace the path of stem weevil (Pempherulus affinis Faust.) infestation in cotton. Presence of bore holes, tunneling by the grub and presence of a section of the grub in the samples of 20 days old stem tissues gave a clear indication that weevil activity starts around 8 to 10 days after sowing (DAS) of cotton contrary to the current theory of 20 DAS. The present investigation assumes significance in the management of stem weevil especially in Southern India.