494 
Observations on the various Insects 
one named Ichneumon Tipukc, by Mr. Kirby, who remarks, "It 
is singular, but most people who are acquainted with the larva of 
the Tipula Tritici mistake this friendly Ichneumon for its parent, 
and thus impute all the mischief to the very creature which is ap- 
pointed to prevent it."* 
This insect is found upon grasses as early as June, and on the 
glumes of the wheat in July and August, when it runs over the 
ears and searches out the infected ones, depositing a single egg in 
each of the larva; by means of its sharp tail. The late Mr. A. 
Mathews, before he left England, sent me specimens, informing 
me that he had found them in the greatest abundance in the 
glumes of the wheat in a field near Sittingbourne, Kent, the be- 
ginning of July. Never having seen this Ichneumon depositing its 
eggs, I cannot satisfy the curiosity of the reader better than by 
transcribing Mr. Kirby's graphic account of its operations, " To 
see our little Ichneumon,'^ says Mr. Kirbj', " deposit its egg in the 
caterpillar of the wheat-fly is a very entertaining sight. In order 
to enjoy this pleasure I placed a number of the latter upon a sheet 
of white paper, at no great distance fi-om each other, and then set 
an Ichneumon down in the midst of them. She began immedi- 
ately to march about, vibrating her antennae very briskly ; a 
larva was soon discovered, upon which shj fixed herself, the vibra- 
tory motion of her antennae increasing to an intense degree ; then 
bending her body obliquely under her breast, she applied her anus 
to the larva, and during the insertion of her aculeus and the depo- 
siting of the egg her antennfe became perfectly still and motion- 
less. Whilst this operation was performing, the larva appeared to 
feel a momentary sensation of pain, for it gave a violent wriggle. 
When all was finished, the little Ichneumon marched off to seek 
for a second, which was obliged to undergo the same opera- 
tion, and so on to as many as it could find in which no egg had 
been before deposited, for it commits only a single egg to each 
larva. I have seen it frequently mount one which had been 
pricked before, but it soon discovered its mistake and left it. The 
size of it is so near that of the Tipula, that I imagine the larva of 
the latter could not support more than one of the former,»and, 
therefore, instinct directs it to deposit only a single egg in each ; 
besides, by this means one Ichneumon will destroy an infinite 
number of larvae." 
These parasites are all included in the Order HyMENorTERA, 
and the Family Ichneumonides adsciti ; the species I am about 
to describe is comprised in the Genus Platygaster ;f it has 
been named by Mr. Kirby Ichneumon Tipuke, and is now de- 
scribed as the — 
* Trans. Linn. Sec, vol. iv. p. 23G. 
•|' So named from some of the larger ones having broad bodies. 
