146 
Observations on the various Insects 
the chaff, many of them quitted the ears and fell to the ground, 
when they buried themselves; these Professor Henslow had good 
reasons to beheve were punctured by the parasitic Ichneumons* but 
we both failed in proving the fact, as the whole of the larvae died. 
Some of them, I believe, were alive in January ; and I entertain the 
same opinion as Mr. Kirby, that they lie as larvae in the transparent 
cases until the spring, when they become chrysalides, for this 
power of remaining in a quiescent larva state is common to many 
Orders of Insects, f and no doubt is a provision to retard their 
premature appearance, and thus secure species from casualties 
which miwht lead to their extinction. This, however, beinor an 
important point in their economy is deserving our attention. In a 
natural state the corn would generally be beaten down in the 
winter; if not, the grains would fall out, get buried, and vegetate; 
or they might lie in the calyx or chaff protected. May not the 
attached larvae, enclosed in their cases, thus pass the winter, and 
in the spring change to pupae in the earth Of course a vast 
quantity would be destroyed by birds and vermin feeding on the 
grain, but the housing and threshing of the corn being an artificial 
system, we must look to the process the insects would be liable to 
in a state of nature. If some infested corn were left to stand at 
harvest and examined weekly, it would in all probability throw 
considerable light upon this puzzling but important stage of their 
economy. The wheat might be transplanted, and protected from 
birds by netting, for tlie object would be to have the ears exposed 
to the variations of the atmosphere, and the earth naturally moist 
to receive the larvae, if they were disposed to leave theirfilmy cells. 
It may also be asked, if the mass of the larvae are transformed to 
flies during or soon after harvest, where do the parent midges come 
from that deposit their eggs in the growing corn whilst in flower 
the following summer? If indeed this insect will live also in the 
glumes of early grasses, which is quite possible, that would solve 
the difficulty; but I am of opinion that the specimens bred by 
Mr. Markwick and Mr. Kirby late in the summer may be con- 
sidered as exceptions to the usual economy of the insect, for at that 
period of the year there is no corn in a fit state to receive the eggs 
of the females. 
The Wheat-midge is not confined to any particular districts 
that I am aware of: it has certainly been observed in Norfolk, 
* Journal of Royal Agr. Soc, vol. ii. p. 26. 
f As the saw-flies or Tenthiedinidae, amongst the Hymenoptera, and 
the Sphingidae and Bonibycidae, amongst the Lepidoptera, some of which 
remain two years or more in their cocoons. Fi</eCurt. Brit. Ent., 2nd 
edit, folio 3, p. 4. 
X It is true that Mr. Kii'by bred a wheat-midge from the ears of wheat,' 
but that was late in the summer, and I am not aware that any one has bred 
the spring broods, which must first deposit their eggs in the growing corn. 
