356 
[Assembly 
after truth, and one so capable of giving to every fact its due weight, 
cannot long remain in error, upon a point so susceptible of demon¬ 
stration as this. 
Its Parasites. 
It is well known that one of the most effectual means for keep¬ 
ing the Hessian fly in check and preventing it from literally swarm¬ 
ing all over our land, has been provided by nature herself. Other 
insects have been created, apparently for the very purpose of prey¬ 
ing upon this, and thus preventing it from becoming inordinately 
multiplied. The world is indebted to Mr. Herrick for much inte¬ 
resting information respecting these insects, the result ot his own 
accurate and patient investigations. As we purpose, should we suc¬ 
ceed in more fully tracing out the history of these and other Ce- 
cidomyian parasites, making them a subject of a separate memoir at 
some future day, we refrain from devoting to them any considerable 
space in the present paper. The general reader, however, will 
scarcely pardon us, if we omit all allusion to them. Me therefore 
subjoin a brief sketch of the contents of this part of Mr. Herrick’s 
article. 
The Hessian fly is preyed upon and devoured by at least four 
other insects. When its eggs are lay eel upon the wheat leaves, they 
are visited by an exceedingly minute four winged fly, (a species of 
Platyguster ,) which punctures the egg and deposites in it tour or 
six eggs of its own; the Hessian fly woim hatches, grows, and 
passes into its flax seed state with these internal foes feeding upon 
it: it now dies, and its destroyers in due time escape from the flax 
seed shell. Three other minute four winged flies, or bees as they 
would be called in common language, destroy the fly wdien in its 
flax seed state. The most common of these, by far, is Say’s Ce- 
raphron destructor. Alighting upon the w r heat stalks, instinct in¬ 
forms them precisely where one of these flax seeds lies concealed. 
They thereupon <( sting” through the sheath of the stalk, and into the 
body of the worm, placing an egg therein, which hatches to a mag¬ 
got, lives upon and devours the w y orra. Such are the means which 
nature has provided for preventing this pest from becoming unduly 
multiplied. And so efficient and inveterate are these foes, that 
more than nine-tenths of all the Hessian fly larva? that have come 
