DIPTERA. ^ 



considerable." In other hands this course has proved of no 

 use whatever. Not to mention other instances, the following 

 appears to be conclusive on this point. About fifty years 

 ago, Mr. Garret Bergen, of Brooklyn, New York, procured two 

 bushels of wheat from the Genesee country, then an unin- 

 fected district, which he sowed in a field adjoining a piece 

 seeded with grain of his own gathering. Both pieces were 

 severely damaged by the Hessian fly, which could not have 

 happened, in the same season, if the eggs of the insect are 

 laid only on the grain. A few years ago he soaked his seed- 

 wheat in strong pickle, and the crop was comparatively free 

 from the fly. In 1839 he tried this experiment again, but not 

 with similar success. 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 afforded 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 Hes- 

 sian fly are thus stated by Mr. Herrick.* " The stouter varie- 

 ties 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 the 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 pupse may be destroyed by burning 

 the wheat-stubble immediately after harvest, and then plough- 

 ing 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 manner." On mature reflection, I am confident that 

 burning the stubble, as originally recommended by Mr. Havens, 



* " American Journal of Science," Vol. XLI., p. 158. 



