350 
OBSERVATIONS ON 
very impatient at tlieir work, continually tossing their heads, 
and rubbing their noses on each other, regardless of the 
driver, so that accidents often ensue. In the heat of the 
day, men are often obliged to desist from ploughing. 
Saddle horses are also very troublesome at such seasons. 
Country people call this insect the nose fly.^ 
ICHNEUMON FLY. 
I SAW lately a small ichneumon fly attack a spider much 
larger than itself on a grass walk. When the spider made 
any resistance, the ichneumon applied her tail to him, 
and stung him with great vehemence, so that he soon 
became dead and motionless. The ichneumon then run- 
ning backward, drew her prey very nimbly over the 
walk into the standing grass. This spider would be de- 
posited in some hole where the ichneumon would lay some 
eggs ; and as soon as the eggs were hatched, the carcass 
would afford ready food for the maggots. 
Perhaps some eggs might be injected into the body of 
the spider, in the act of stinging. Some ichneumons 
deposit their eggs in the aurelia of moths and buttei flies.* 
^ Is not this insect the (Estrus nasalis of LinnfEus, so well described 
by Mr. Clark in the third volume of the Linnean Transactions, under 
the name of CEstrus veterinus. — Markwick. 
In my " Naturalist's Calendar" for 1795, July 21st, I find the 
following note : — 
It is not uncommon for some of the species of ichneumon flies to 
deposit their eggs in the chrysalis of a butterfly : some time ago I put 
two of the chrysalis of a butterfly into a box, and covered it with 
gauze, to discover what species of butterfly they would produce ; but 
instead of a butterfly, one of them produced a number of small ich- 
neumon flies. 
There are many instances of the great service these little insects are 
to mankind in reducing the number of noxious insects, by depositing 
their eggs in the soft bodies of their larvce ; but none more remarkable 
than that of the Ichneumon tipulce, which pierces the tender body and 
deposits its eggs in the larva of the Tipula tritici, \_Cecidomyia tritici, 
Kirby — Ed.] an insect which, when it abounds greatly, is very pre- 
judicial to the grains of wheat. This operation I have frequently seen 
it perform with wonder and delight. — Markwick. 
