DIPTERA. 457 



so that no insect could get access to the interior. The paper 

 was sufficiently perforated with pin holes for the admission of 

 air. The tumbler with its contents was daily watched by 

 myself to discover the hatching of the eggs. About the mid- 

 dle of the fifteenth day from the deposit of the eggs, I was so 

 fortunate as to discover a very small maggot or worm, of a 

 reddish cast, making its way with considerable activity down 

 the blade, and saw it till it disappeared between the blade and 

 stem of the plant. This, I have no doubt, was the produce of 

 one of the eggs, and would, I presume, have hatched much 

 sooner, had the plant remained in, the field. It was my inten- 

 tion to have carried on the experiment, by endeavoring to 

 hatch out the insect from the flax-seed state into the perfect 

 fly again; but being called from home, the plant was suffered 

 to perish. The fly that I caught on the blade of the wheat, 

 as above stated, I enclosed in a letter to Mr. John S. Skinner, 

 the editor of ' The American Farmer,' of Baltimore, who pro- 

 nounced it to be a genuine Hessian fly, and identical in ap- 

 pearance with others recently received from Virginia." Dr. 

 Chapman agrees with this writer in saying, that the Hessian 

 fly lays her eggs in the small creases of the young leaves of 

 the wheat. Mr. Havens states, that the fly lays her eggs on 

 the leaves. In the fortieth number of " The Connecticut Far- 

 mer's Gazette," Mr. Herrick says, "I have repeatedly, both 

 in autumn and in spring, seen the Hessian fly in the act of 

 depositing eggs on wheat, and have always found, that she 

 selects for this purpose the leaves of the young plant. The 

 eggs are laid in various numbers on the upper surface of the 

 strap-shaped portion (or blade) of the leaf." His remarks in 

 Professor Silliman's Journal are to the same effect. Other 

 authorities on this point might be mentioned; but the fore- 

 going are sufficient, in my opinion, to establish the fact, that 

 the Hessian fly lays her eggs on the leaves of wheat soon after 

 the plants are up. " The number on a single leaf," says Mr. 

 Herrick, "is often twenty or thu'ty, and sometimes much 

 greater. In these cases many of the larvae must perish. The 

 egg is about a fiftieth of an inch long, and four thousandths 

 of an inch in diameter, cylindrical, translucent, and of a pale 

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