24 BULLETIN 808, U. S. DEPARTMENT OF AGRICULTURE. 



affairs, in that there was no very simple remedy at hand ; for example, 

 simply spraying the wheat would not cure the trouble. 



The writer has studied the situation for years and has found that 

 most if not all of the so-called remedies are useless. For several 

 winters futile attempts were made to bum over stubble fields in 

 Indiana. In the first place the ground must be frozen or the 

 burning will destroy the young clover and at no time during 

 the winter could the stubble be burned under these conditions. This 

 would be the simplest of all remedies if it were practicable, although 

 it would destroy a source of humus. Another supposed remedy was 

 to plant wheat as far from the old stubble as possible. This is folly 

 unless the farm in question covers an area of several square miles. 

 The jointworm can fly and may be carried by the wind at least for a 

 mile. The suggestion of sowing wheat early, in years of scarcity of 

 the Hessian Q.Y, is equally futile. V. L. Wildermuth, of this bureau, 

 made observations on 51 fields at Groveport, Ohio, in 1909, in order 

 to determine the effect of early and late sowings in relation to joint- 

 worm injury. Twenty-eight fields sown from September 10 to 30, 

 with an average date of September 24, showed an average infestation 

 of 38 per cent, with an average yield of 8| bushels per acre; 15 of 

 these fields produced grain of good, 10 of medium, and 3 of poor 

 quality. On the other hand, 23 fields sown October 1 to 24, with 

 average date of October 10, showed an average infestation of 19 per 

 cent with an average yield of 20 bushels per acre; 11 of these pro- 

 duced grain of good, 9 of medium, and 3 of poor quality. These 

 observations show also that whether the wheat were sown early or 

 late the wheat on poor ground always was infested to a greater 

 degree, provided the fields were equally distant from the source of 

 infestation. The writer's observations confirm this idea. 



Some writers have suggested that the larvae would be destroyed if 

 the infested stubble should pass through stables and then be sub- 

 jected to the process of decomposition incidental to composted ma- 

 nure. The writer therefore placed infested stubbles in horse stables 

 and allowed them to become mixed with the droppings in the ordi- 

 nary way. They were then removed to the center of a heap of 

 manure and part of them allowed to remain in the manure all winter 

 while the remainder were removed after having remained in it for 

 two weeks, and then scattered on the ground and allowed to remain 

 there undisturbed throughout the winter and spring. Those remain- 

 ing in the manure pile were removed the last week in March, and 

 placed in confinement for observation, as were those that were scat- 

 tered on the ground in early winter. Each lot produced about 

 the same number of adults as did stubble that was allowed to winter 

 in the usual manner in the field. This experiment certainly indi- 



