DIPTERA. 431 



strong pickle, and the crop was comparatively free from the fly. 

 In 1S39 he tried this experiment again, but not with similar suc- 

 cess. In 1840 he sowed without previously soaking the grain, 

 and his crop was uninjured. He says, moreover, that he has 

 uniformly found the grain most affected in spots, usually near the 

 edges of the field, where long grass and weeds grew, which af- 

 forded shelter and protection to the fly. This fact, he thinks, 

 affords another proof, that the egg is not deposited in the grain. 

 I regret that my limits will not permit me to extract the whole of 

 Mr. Bergen's interesting remarks, which may be found in number 

 eight, of the eighth volume of " The Cultivator," published in 

 Albany in August, 1841. The best modes of preventing the 

 ravages of the Hessian fly are thus stated by Mr. Herrick.* 

 " The stouter varieties of wheat ought always to be chosen, and 

 the land should be kept in good condition. If fall wheat is sown 

 late, some of the eggs will be avoided, but risk of winter-killing 

 the plants will be incurred. If cattle are permitted to graze the 

 wheat fields during the fall, they will devour many of the eggs. 

 A large number of the pupae may be destroyed by burning the 

 wheat-stubble immediately after harvest, and then ploughing and 

 harrowing the land. This method will undoubtedly do much 

 good. As the Hessian fly also lays its eggs, to some extent, 

 on rye and barley, these crops should be treated in a similar man- 

 ner." It is found that luxuriant crops more often escape injury 

 than those that are thin and light. Steeping the grain and rolling 

 it in plaster or lime tends to promote a rapid and vigorous growth, 

 and will therefore prove beneficial. Sowing the fields with wood 

 ashes, in the proportion of two bushels to an acre, in the autumn, 

 and again in the first and last weeks in April, and as late in the 

 month of May as the sower can pass over the wheat without in- 

 jury to it, has been found useful. f Favorable reports have been 

 made upon the practice of allowing sheep to feed off the crop 

 late in the autumn, and it has also been recommended to turn 

 them into the fields again in the spring, in order to retard the 

 growth of the plant till after the fly has disappeared. J Too 



* " American Journal of Science," Vol. XLI., p. 358. 



t " Cultivator," Vol. V., p. 59. 



t " Cultivator," Vol. IV., p. 110, and Vol. V., p. 49. 



