On Some Parasites Found in Association with the Stem Weevil Pest of Cotton in South India and Their Role in Its Biologial Control

Abstract

It is now over two decades since the cotton stem weevil Pempheres affinis,F.began to attract some attention as a fairly important pest of cotton in South India,and the first paper (1)on the general features and life history of this insect was published by the senior uthor.Since them.this pest,which was in the early yars confined chiefly to the cambodia variety of cotton.has been directing its attentions to other cottons and distributing itself fairly widely in the cotton areas of South India.As a consequence.special attention has had to be paid to this insect along with other important pests of cotton viz.the holl worms,and even the help of legislation had to be resorted to for the control of these important pests.Side by side, intensive studies on the different aspects of the problems connected with this insect have also been carried out by the Government Entomologist and by a special staff appointed for this work by the Indian Central Cotton Committee.The peculiar habits of this weevil as an internal feeder in its destructive stages have made itrather ifficult to rackle it by means of the ordinary mechanical or inscticidal methods of control.and it is found that the only possible means of keeping the pest under some control must mainly consist of prophylactic ciltural means and plant sanitation.the breeding of resistant strains of cotton.or by trials in biological methds by the use of parasites or predators.Speaking of biological methods and the agencies in that direction.Speaking of biological methods and the agencies in that directionn.with which this paper is mainly concerned.it is needless to add that it is in the first place essential to find out whether any such natural enemies really exist some definite ideas regarding their potentiality before any control measures in that anddirection are attempted.With a view to find out if the pest is subject to the attacks of such naturalenemies the authors have been carrying on some work.and the experimence of the past two or three years has so far shown that this insect,unlike some of our common insect pests. is not commonly subject to potentiality before any befrore three years has so far shown that this insect unlike some of our common insect pests.is not commonly subject to parasites or predators ,and till now studies in this direction have revealed the existence of only a few parasitic wasps in comparatively very small numbes associated with the developing stage of this weavil pest.These being the first definitely identified and reared records of insect enemies of this stem weevil.theauthors have thought it desirable to presnt this fact in this short paper with the available systamatic and biological notes gathered so far regarding these parasites and their role as natural enemies.

DOI

https://doi.org/10.29321/MAJ.10.002103

Pages

102 - 106

Creative Commons

Copyright

© The Author(s), 2026. Published by Madras Agricultural Students' Union in Madras Agricultural Journal (MAJ). This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited by the user.

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