CHTNCH BUG WEST OF MISSISSIPPI RIVER. 51 



numbers that reach maturity, many young being killed during a 

 period of wet weather attended by hard dashing rains. Dry weather 

 is most favorable to their development in abundance. The injury to 

 wheat and corn is often severe, sometimes resulting in almost com- 

 plete destruction of the latter crop after serious injury to the former. 



During the severe winter of 1909 and 1910 about 20 per cent 

 of the bugs died normally in the clumps of red sedge grass, where they 

 hibernate. 



Experiments in Kansas made during the winter of 1909-10 showed 

 that as high as 75 per cent of the hibernating chinch bugs could be 

 killed by burning this grass. The best time to burn is in the fall, when 

 the grass is as dry as possible. It is not necessary that the flame come 

 in actual contact with the bugs. 



The effectiveness of the burning is almost entirely dependent 

 upon the cooperation of the farmers in infested localities. Neglect 

 to destroy chinch bugs collected in these grasses will often result in 

 serious injury, if not indeed a complete destruction of wheat, corn, 

 cane, and kafir. 



Next to burning, the dust and coal-tar barriers are the most 

 effective remedies, and should be used while the bugs are migrating 

 from wheat to corn. These barriers must be properly made, and 

 demand constant attention to be of any value. 



Many bugs can be killed while massed on the first rows of corn 

 by applying a torch or spraying with kerosene emulsion or proprietary 

 spraying materials. 



Plowing under infested crops is not recommended unless the work 

 is done very thoroughly and followed by a crop not susceptible to 

 chinch-bug attack. 



Barriers made of piles of green corn are of no value, and are not 

 recommended. 



The " white fungus/' can not be depended upon to exterminate the 

 chinch bugs. This fungus is very dependent upon moist weather 

 conditions for its rapid development and diffusion. It can usually 

 be secured by collecting live or dead chinch bugs from the sedge 

 grass, and placing them under proper conditions of temperature 

 and moisture. This fungus has many host insects, and is generally 

 present where chinch bugs are found in destructive numbers. 



Laboratory experiments show that this fungus is present in greatest 

 abundance among old spent adults, or those bugs that are in a 

 weakened condition. Also that it will grow upon dead bugs. This 

 will partially account for the fact that the time of its greatest abun- 

 dance in the fields occurs after the hibernating bugs have laid their 

 eggs and are dying normally. These bugs have performed their mis- 

 sion of laying eggs, and are comparatively harmless. 



