344 OBSER VA TIONS ON INSECTS. 



Is not this insect the Oestrus nasalis of Linnseus, so well 

 described by Mr. Clark in the third volume of the 

 Linncean Transactions, under the name of Oestrus 

 veterinus ? MARKWICK. 



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 back- 

 ward, 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 butter- 

 fly, 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 

 larvce ; but none more remarkable than that of the 



