OBSERVATIONS ON INSECTS AND VERMES 361 



also very troublesome at such seasons. Country-people call 

 this insect the nose-fly. WHITE. 



Is not this insect the oestrus nasalis of Linnaeus, so well 

 described by Mr. Clark in the third volume of the " Linnsean 

 Transactions," under the name of oestrus veterinus ? MARK- 

 WICK. 



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 

 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 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 butterflies. WHITE. 



In my "Naturalist's Calendar" for 1795, July 2ist, 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 chrysalises of a butterfly into a box, 

 and covered it with gauze, to discover what species of butter- 

 fly 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 

 larvae ; 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, when it 

 abounds greatly, is very prejudicial to the grains of wheat. 

 This operation I have frequently seen it perform with wonder 

 and delight. MARKWICK. 



