OBSERVATIONS ON INSECTS AND VERMES. 293 
OESTRUS CURYICAUDA. 
This insect lays its nits or eggs on horses' legs, flanks, &c., each on a 
single hair. The maggots, when hatched, do not enter the horses' 
skins, but fall to the ground. It seems to abound most in moist, 
moorish places, though sometimes seen in the uplands. — White. 
ISrOSE-FLY. 
About the beginning of July, a species of flj (musca) obtains, which 
proves very tormenting to horses, trying still to enter their nostrils 
and ears, and actually laying their eggs in the latter of those organs, or 
perhaps in both. When these abound, horses in woodland districts 
become very impatient at their 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. — White. 
Is not this insect the Oestrus nasalis of Linnasus, so well described 
by Mr. Clark in the third volume of the " Linnsean Transactions," 
under the name of Oestrus veterinus ? — Markwick. 
ICHN"EUMON 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 ich- 
neumon then running backward drew her prey very nimbly over the 
walk into the standing grass. This spider would be deposited in some 
hole where the ichneumon would lay some eggs ; and as soon as the 
eggs were hatched, the carcase 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 butterflies. — White. 
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 chrysales 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 ichneumon 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 larv(B ; but none more remarkable 
than that of the ichneumon tipulce, which pierces the tender bodies and 
deposits its eggs in the larva of the Tipula tritici, an insect which, 
