SB 

 818 

 C578 

 ENT 



Circular No. 70. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY, 



L. O. HOWARD, Entomologist and Chief of Bureau. 



THE HESSIAX FLY. 



{Mayetwla \^CeckJ<jinijiti] deslrvctor Say.) 



By F. M. Webster, 



In Cliarge of Cereal and For(tge-plaid Insect Investigations. 



Probably no other insect causes more damage to the Avheat crop 

 of the United States 

 than the Hessian ii}', 

 though the chinch bug 

 is doubtless a close 

 second. During years 

 when it is excessively 

 abundant, hundreds 

 of thousands of acres 

 of wheat may be either 

 totally destroyed or so 

 badly injured as to re- 

 duce the 3'ield 50 to 75 

 per cent, and the mon- 

 etary losses expressed 

 in dollars would run 

 far up into the mil- 

 lions. This insect is an 

 old depredator, in the 

 sense that it has long 

 been known to ravage 

 our wheat fields, yet 

 farmers are, in many cases, still at a loss regarding the best methods 

 of wardinj^ off its devastation. 



EARLY HISTORY IN AMERICA. 



The common name, "Hessian fly,'' was long ago bestowed upon this 

 insect by Americans, because of its having conunitted some depreda- 

 tions on Long Island, New York, in ITT9, in the vicinity of Lord 

 Howe's old encampment of three years before. The Hessian merce- 



(1) 



FiG.l. — The Hessian fly {Mayctiola destructor): Adult I'einale, mnoh 

 enlarged (original). 



