On the Hessian Fly, 



four days in September, and first week in October, is 

 the best time for sowing wheat ; about which time I have 

 for several years past, bq^n in the practice of sowing, 

 and though a few of the insect in the caterpillar state 

 may appear in the young wheat, they are so few as to do 

 but litde injury. 



Thy friend, 



Isaac Chapman, 



Thomas G, Kennedy, Esq, 



Sec, of the Agric, Soc. of Bucks County, 



[Mr. Worth of Bucks County, Pennsylvania, says that there 

 are certainly three annual generations of the fly, instead of two 

 as stated by Dr. Chapman, who, he thinks, has " blended the first 

 nd second." The deposit of the eggs for the third generation, 

 according tu Mr. Worth, begins about the 15th August, and is 

 carried on till winter. The fly remains in the pupa state dur- 

 ing the winter, except in some instances, where it is exposed to 

 a proper degree of warmth, which is the case in the straw about 

 barns. He has found it occasionally from December to March 

 inclusive, about the windows of a room where fire was kept, and 

 he has seen it in the fields, as late as the 25th of November.* 

 Another farmer has seen the fly " quite active, when the ground 

 was hard frozen ;" and a third, saw the fly in the very act of 

 depositing its eggs on the 5th of October, in wheat that had been 

 sown on the 14th of the preceding September.t No doubt can 

 therefore be entertained of there being at least three generations 

 of this insect in one year. M.] 



* Memoirs of the Penn. Agric. Soc. p. 168, 169, and American Farmer, vol. S 

 p. 189. o I . > , 



f American Farmer, vol. 2. p. 'ISS. 



