Level Of Infestation And Differential Response Of Cotton Plants
To Damage By The Stem Weevil, Pempherulus Affinis
 

S.Mohan^1*, P.Pretheep-Kumar¹, M.Sivakumar², N.Balakrishnan³, R.Ravikesavan^4
1Department of Entomology, Tamil Nadu Agricultural University,
Coimbatore- 641 003, Tamil Nadu, (INDIA)
²Department of Nematology, Tamil Nadu Agricultural University,
Coimbatore-641 003, Tamil Nadu (INDIA)
³Department of Biotechnology, Tamil Nadu Agricultural University,
Coimbatore-641 003, Tamil Nadu, (INDIA)
⁴Department of Cotton, Tamil Nadu Agricultural University,
Coimbatore-641 003, Tamil Nadu, (INDIA)

Histopathological studies carried out with the stem tissues 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.