306 NORTH AMERICAN INSECTS. 



and upon that which grows in autumn, so that when there 

 are two crops of grain a year there will be at least two gen 

 erations of these flies. 



Miss Margaretta H. Morris, of Gerrnantown, Pennsyl 

 vania, whose labors in the science of entomology are well 

 known, and whose articles, published in the &quot; Transactions 

 of the American Philosophical Society,&quot; have gained her 

 great reputation, has discovered another species of Hessian- 

 fly which lives altogether inside of the stalk, and which she 

 calls Cecidomyia culmicola. 



The means used to destroy these noxious insects have 

 been very various, and not always as successful as antici 

 pated. Miss Morris recommends obtaining seed-wheat 

 from places whore the fly lias never been. Mr. Garret 

 Bergen, of Brooklyn, New York, soaked his seed-wheat in 

 strong pickle, and the crop was free from the fly. Mr. 

 Herri ck advises to burn the stubble of wheat, rye, and bar 

 ley immediately after the harvest, and then plow and har 

 row the land, which process, he says, will destroy the largest 

 part of the puptc that are left. 



Another very common insect of this order is the CHEESE- 

 FLY (Piophila casci), which is not larger than a small ant, 

 of a brown color, its neck shining like a mirror, and its 

 wings larger than the body. 



The maggots of this fly arc better known than the per 

 fect insect, and are almost universally found in cheese, al 

 though many persons are so little acquainted with the na 

 ture of these disgusting animals that they eagerly devour 

 them in fact, consider them as the most delicious portion 

 of the cheese. It was formerly believed that these maggots 

 originated by the putrefaction of the cheese ; but the con 

 trary is rather the case, for they crumble the cheese, admit 

 ting air into it, and soil it with their fluid excrement, which 

 causes putrefaction, particularly when many of them die, 

 as is often the case when the perfect insect has been etung 



