426 ^ INSECTS INJURIOUS TO VEGETATION. 



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 presunae, have hatched much sooner, had the 

 plant remained in the field. It was my intention to have carried 

 on the experiment, b)'^ endeavouring to hatch out the insect frorh 

 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 pronounced it to be- a genuine Hes- 

 sian fly, and identical in appearance 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, in an article on this 

 insect, which will again be referred to, states, that the fly lays 

 her eggs on the leaves. In the fortieth number of " The Con- 

 necticut Farmer's Gazette," Mr. Herrick says, " I have re- 

 peatedly, 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 arfe to the same effect. Other authorities on 

 this point might be mentioned ; but. the foregoing are sufficient, 

 in my opinion, to establish the fact, that the Hessian fly lays her 

 eggs oti the leaves of wheat soon after the plants are up. " The 

 number on a single leaf," says Mr. Herrick, " is often twenty 

 or thirty, 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 red color." Mr. Tilghman was cor- 

 rect in supposing that the eggs would hatch in less than fifteen 

 days, under favorable circumstances ; for, if the weather be warm, 

 they commonly hatch in four days after they are laid. The niag- 

 gots, when they first come out of the shells, are of a pale red 

 color. Forthwith they crawl down the leaf, and work their way 

 between it and the main stalk, passing downwards till they come 

 to a joint, just above which they remain, a little below the sur- 



