DIPTERA. 423 



It was first observed in the year 1776, in the neighbourhood of 

 Sir WilHam Howe's debarkation on Staten Island, and at Flat 

 Bush, on the west end of Long Island. Having multiplied in 

 these places, the insects gradually spread over the southern parts 

 of New York and Connecticut, and continued to proceed inland 

 at the rate of fifteen or twenty miles a year. They reached 

 Saratoga, two hundred miles from their original station, in 1789. 

 Dr. Chapman says, that they were found west of the Alleghany 

 mountains in 1797 ; from their progress through the country, 

 having apparently advanced about thirty miles every summer. 

 Wheat, rye, barley, and even timothy grass were attacked by 

 them ; and so great were their ravages in the larva state, that the 

 cultivation of wheat was abandoned in many places where they 

 had established themselves.* In a communication by Mr. J. W. 

 Jeffreys, published in the sixth volume of Buel's " Cultivator," 

 it is stated, that soon after the battle of Guilford, in North Caro- 

 lina, the wheat crops were destroyed by the Hessian fly in 

 Orange county, through which the British army, composed in 

 part of Hessian soldiers, had previously p'assed. Although it 

 is possible that, in this instance, the chinch bug may have been 

 mistaken for the Hessian fly, the remark shows how prevalent 

 was the belief respecting the introduction of the latter. The 

 foregoing statements, taken in connexion with the habits of the 

 Hessian fly, induce me to think that the common opinion relative 

 to its origin is deserving of some credit, although we are as yet 

 without any positive evidence of the existence of this insect in 

 Germany. 



The following brief history of the habits and transformations 

 of the Hessian fly will be found to agree essentially with the ex- 

 cellent observations on this insect, written in the year 1797, by 

 Dr. Isaac Chapman, and published in the fifth volume of the 

 " Memoirs of the Philadelphia Society for promoting Agricul- 

 ture." Mr. Herrick has kindly permitted me to make free use 

 of his valuable account of this insect, contained in the forty-first 

 volume of " The American Journal of Science," and of other 



* " Encyclopfedia Britannica," and Dobson's " Encyclopcedia," Vol. VIII., ar- 

 ticle Hessian Fly. 



