FAMILY TIPULID.E. 175 



is found attached to the stem, near or upon the first and second joints. Dr. Fitch remarks 

 that the sec ml brood is less injurious than the first, in consequence of the more advanced 

 state of the grain and the firmer consistence of the stalk. The worm, by its irritation, 

 diverts the current of flowing sap to itself, and produces an enlargement of the stem at 

 the place where it is attached. The culm is weakened by the change of structure that has 

 taken place in consequence of the numerous worms usually congregated near its base. 

 By the first of June, the worm has changed into its flaccid state ; and about the last of 

 July, or early in August, the mature insect, the fly, appears for the second time. This last 

 brood of flies is now ready for the young wheat that may be sowed, upon the leaves of 

 which they deposit their eggs, and there finish their transformations so as to appear in 

 New-York the last of April. 



Thus careful observation has proved that but two broods appear during the year, though 

 it has been maintaintd by some observers that there are three. This latter opinion seems 

 to have arisen from the fact that an entire brood does not appear at once, or on the same 

 day, but the fly may and does continue to come forth for as many as ten or twelve days 

 after the first of the brood are hatched. 



The most important question which stands connected with the hessian-fly, is, By what 

 means shall the fanner protect himself from its ravages I Now we have very slight grounds 

 for expecting, or even for hoping that a remedy will ever be found that shall meet our 

 wishes in this respect. The evil is rather to be warded off by a judicious use of means that 

 are related to the habits of the fly, and to the habitudes of the wheat plant itself. When 

 a district, however, is extensively affected, the true course undoubtedly is to cease cul- 

 tivating wheat, and perhaps barley also, until the fly has disappeared. 



Recurring to the habits of the insect, the most significant are the time of its appearance, 

 and the time it continues in its perfect state, during which it is engaged in laying its eggs, 

 an operation, the exact time of which it is essential for us to know in this case ; and it is 

 a law of nature in the insect class, that when swarms are produced, they come forth at 

 regular periods of time. The habits alluded to are well known in the case of the hessian- 

 fly. As to the time when the insect appears, it is established by observation that about the 

 first of May, or at time in the spring when the earliest trees and plants are flowering, this 

 fly is maturing, and comes forth near the time specified ; and the first brood is hatched 

 from esgs laid in autumn. These two facts unite to suggest the same precautionary measure 

 to be taken for the eradication of the fly from both the winter and the spring crop, name- 

 ly, to delay sowing the grain until the fly has disappeared, or to that period when the 

 plant will come up too late for the deposit of eggs upon it. Experience has proved the 

 efficacy of late sowing in both kinds of wheat. 



Another remedy is connected with the place where the eggs are deposited, and where 

 the transformations are undergone. It seems established that the real hessian-fly deposits 

 its eggs upon the young leaf, near the stem, and near the base of the stem. The consequence 



