9 PESTS OF THE COTTON PLANT. 



The caterpillars are short and thick, not more than two-thirds of an 

 inch long when full grown. The colour is very variable, a mixture of 

 white, green and black, with orange spots. The predominant colour may 

 be a dull greenish white, with black marks and small orange spots, or 

 black, with an irregular band of greenish white from head to tail with 

 orange spots on the sides. There are tubercles on each segment, bearing 

 hairs ; the orange spots appear only in fairly advanced larvae and the 

 quite young caterpillars are darker. Legs and prolegs are present, the 

 head is dark in colour and there is a dark prothoracic shield. 



The cocoon is less than half an inch long, oval and flattened, made 

 of grey silk closely woven. It has a resemblance to the grey woolly buds 

 that fall off the cotton-plant. 



Remedies. The treatment of this pest depends upon the conditions 

 under which cotton is grown, and the variety of cotton. Certain varieties 

 show a complete or partial immunity to it, but it is uncertain how far 

 any variety will prove immune when grown as a field crop. The 

 varieties now grown as field crops are apparently all attacked. There is 

 only one direct remedy that can at present be advised for general 

 adoption. It is applicable only to cottons which produce a crop of bolls 

 at one time and is ineffective in varieties which continue to produce 

 bolls over a long period. It consists in destroying as many of the 

 caterpillars as possible in the shoots of the cotton or in the first bolls. 

 The first brood of boll-worms is found in the shoots and in the early 

 bolls ; the dead shoots are readily seen and destroyed, the attacked bolls 

 are easily found and burnt. There is no loss of crop, as these bolls will 

 never yield cotton, and it is very important to check the first brood which 

 soon becomes a very large second brood if left alone. This method can 

 be carried to the degree of removing all the early bolls. 



Another treatment, still in the experimental stage, consists in 

 spraying with lead arseniate when the bolls first form. A preventive 

 measure of some importance is to remove the plants when the crop is 

 picked. It is not uncommon to see stray plants still living in the hot 

 weather after the crop is harvested, which help the pest to increase at a 

 very critical time, especially if showers fall and the cotton makes a little 

 growth. 



The importance of bhindi as an alternative food-plant is also great. 

 "Where bhindi is grown, the insects can breed in it when cotton 

 is not available. Where cotton is a staple crop, bhindi should not be 

 grown except when there is cotton. It should not be grown in Gujarat, 

 for instance, from February to August, as it helps the pest to increase 

 during the hot weather and early rains, providing a large number of 



