496 Observations on the various Insects 
lented naturalist considered it to be connected with our wheat- 
fields.* 
The second species described by Mr. Kirby he has named Ich- 
neumon iNSERENS : it is apparently a Platvgaster ;f but as I 
have not been able to find the specimen in his collection, I must 
be satisfied in transcribing his account and copying his figures. 
He says, " Upon the 7th of June I observed a very minute Ichneu- 
mon exceedingly busy upon the ears of wheat, which, at first, 
I took for Ichneumon Tipulce ; but upon a closer examination I 
found it to be a species entirely distinct, as will appear when 
I come to describe it. As soon as I was convinced of this, and 
observed that it pierced the florets at a time when no larvae had 
made their appearance, I conjectured that it must lay its eggs in 
the eggs of the Tipula." " This insect is furnished with an aculeus 
three or four times its own length (fig. c), which is finer than a 
hair and nearly as flexile ; this is commonly concealed within the 
abdomen, but when the animal is engaged in laying its eggs it is 
exserted : one day it gave me a full opportunity of examining this 
process. It inserts its aculeus between the valvules of the corolla 
near the top of the floret ; its antennaj are then nearly doubled and 
motionless, its thorax is elevated, and its head and abdomen de- 
pressed ; the latter, when it withdraws the aculeus, is moved fre- 
quently from side to side before it can extricate it. This insect has 
allowed me to examine its operations under a lens for six or seven 
minutes : upon opening the floret into which it had introduced its 
aculeus, I could find neither egg nor larva of the Tipula ; but, 
upon examining it very closely under three glasses, I (Hscovered, 
scattered over one of the valvules of the corolla, a number of 
globular eggs extremely minute, evidently not those of that insect. 
It is possible that there were in this floret eggs of the latter, which 
might be destroyed upon opening it, or escape my observation. 
At other times I have found eggs of the Tipula Tritici, and once 
some larvae, in florets upon which I had observed this Ichneumon 
busy." From the time in which it first makes its appearance, 
ten days before the hatching of the first larvae, I am inclined to 
adoj^t my original conjecture, that the eggs are its prey ; and yet 
there seems not to be a sufficient disproportion between the size of 
the one and the other for this p\irpose ; at least, it must take more 
than one to nourish a larva of the Ichneumon to its proper size."| 
• Curtis's Brit. Ent., fol. 300 ; and Guide, Genus 585, where 108 species 
«,re recorded. 
•f I have included it in the Genus /wostonma in the ' Guide,' a Genus 
which has been formed out of Platijgaster ; but whether I have been ris;ht 
in its location, I am unable at present to determine for want of materials. 
J Trans. Linn. Soc, vol. v. p. 102. 
