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 Germantown, Pennsyl- 
vania, whose labors in the science of entomology are well 
known, and whose articles, published in the ‘ Transactions 
of the American Philosophical Society,” have gained her 
great reputation, has discovered another species of Hessian- 
fly which lives altogether inside of the stalk, and which she 
-ealls 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 where the fly has 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. 
Herrick 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 pupz that are left. 
Another very common insect of this order is the CHEESE- 
FLY (Piophila casei), 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 are 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 stung 
