4 THE COTTON STAINER. 



at about the time of the opening of the bolls. The brownish color 

 appears to arise from the injured seed. At any rate the examination 

 of considerable seed cotton showed practically invariably that the 

 stain was most dense immediately surrounding the seed. Another 

 reason for the conclusion at which Dr. Morrill arrived was that the 

 amount of staining found was generally entirely too great to be 

 accounted for by the excrement of the insect, although there is no 

 doubt that a portion of this stain is due to that cause. ^ 



REPRESSION. 



One habit of the insect makes it amenable to simple control meas- 

 ures. This is its tendency to develop in close colonies restricted for a 

 long time to one or at most to a very few plants. At such times the 

 red color of the bugs makes them conspicuous objects. When they 

 are found, it is an easy matter to destroy them by jarring them into 

 buckets containing a little water and a few drops of kerosene. This 

 will be found perfectly satisfactory and an economical method of 

 control. In special cases the purchase of spraying macliinery and 

 the application of kerosene emulsion may be justified. By practicing 

 the destruction of the colonies scrupulously through the season 

 practically all can be destroyed before they have an opportunity to 

 injure cultivated plants. As has been noted, the weed known as 

 Spanish cocklebur should be watched especially. Of course the 

 ])lanter mil realize that preventing the growing of this useless plant 

 and others that support the bug will have the effect of an insurance 

 against injury to his crops. 



At certain seasons, especially in the fall and early spring, the cotton 

 stainer can be attracted to baits. Cottonseed or sugar cane are 

 very suitable for this purpose, more especially the former. If small 

 heaps of cottonseed are placed in the cotton fields or in their imme- 

 diate vicinity, it will be found that they soon become densely cov- 

 ered by the stainers. At such times they may easily be destroyed 

 by the use of hot water or kerosene. 



Mr. P. L. Guppy has published an account (Cir. No. 6, Board of 

 Agriculture of Trinidad and Tobago, Dec. 17, 1911) of experiments in 

 using baits formed of seed cotton for attracting the stainers. Small 

 balls of seed cotton were hung on the cotton plants. These balls 

 consisted of a large handful of seed cotton wrapped with twine. It 

 was found that large numbers of the stainers were attracted to these 

 balls. At intervals of several days the balls were carefully removed 

 from the plants and shaken over receptacles containing oil. It is 



1 Recently Mr. P. L. Guppy (Cir. No. 6, Board of Agriculture of Trinidad and Tobago, p. 131, Dec. 17, 

 1911) verified Dr. Morrill's finding as to the origin of the stain. He states: "The damage is done l^efore the 

 bolls open by the insect piercing the walls in order to obtain the juices and the cell sap exudes through the 

 punctures thus made to the cotton lint which is being formed inside the boll." This statement refers to 

 Dysdercus howardi Ballou. 



