STATE AGRICULTURAL SOCIETY. 
823 
midoe. destroyers, chances op the parasites’ reaching ds. 
To obtain all the larvae it would be obliged to part the chaffs 
from all the kernels, whereby no wheat whatever would be pro¬ 
duced. Thus we are indebted to this bird that the grain which 
we do gather is not dwarfed and shrunken to a much greater 
degree than it is. And were the natural .parasites of the midge 
introduced into this country, it is very evident that the addi¬ 
tional aid which this bird would give to their work would subdue 
this insect here much more effectually and completely than it is 
subdued in Europe. 
Before leaving this branch of our subject, the reader will be 
anxious to know why these parasites of the midge have not fol¬ 
lowed it to this country, and how much longer we must probably 
wait for them to arrive here. Let us look then, at the chances 
which exist for these insects to be brought across the Atlantic. 
In what manner do insects become transported to such great dis¬ 
tances ? We see how this may be done in the case of the Hessian 
fly. Its larvae remaining dormant in the straw of the wheat for 
a number of weeks will be liable to be carried anywhere that the 
straw is taken. We see its parasites also cradled within these 
larvte in the straw, and thus know that they too will be equally 
as liable as the Hessian fly itself to be conveyed wherever it is 
conveyed. How is it with respect to the midge and its parasites ? 
We see the larvae of the midge lying dormant in the dry wheat 
heads for months, whereby they may be carried wherever any 
unthreshed wheat happens to be carried. And how is it as to 
its parasites ? The egg parasite, I. inserens, has never been in¬ 
vestigated, and thus we are unable to judge of this matter with 
respect to it. But of the larva parasite, P. Tipula, which the 
British writers regard as the most important and useful one of 
these parasites, we are sufficiently informed. Mr. Kirby tells us 
that when several of the larvae of the midge are scattered about 
upon a sheet of paper, and one of these parasites is set down 
among them, it immediately passes around from one to another, 
stinging and inserting an egg in each one of them. Thus we 
know it is when the midge larvm are openly exposed, crawling 
about upon the wheat heads and going down the straw to the 
ground, that this parasite is on the alert to deposit its eggs in 
them. And Prof. Henslow’s researches, several years ago, im¬ 
pressed him with the idea that it w f as only those larvae which 
were stung or ichneuiuonized which descended into the ground, 
t 
