88 Mr CusLri&'& Oijhvdtiofis (itt J/>hi(fc-s. 



fycamore, which is much more agile than many of this race, en- 

 deavour to avoid the Ichneumon with great addrcfs. 



There is, perhaps, no genus of infects which in their iaiva or 

 maggot ftate feed on fuch a variety of food as the Mufca, or Fly. 

 There is fcarcely a part of nature, either animate or inanimate, 

 in which they are not to be met with. Onedivifion of them, called 

 by Linnaeus Mufcrt apbiJivorte, feeds entirely on aphides. Of the 

 different fpecies of aphidivorous flies, which are numerous, having 

 nioflly bodies variegated with tranfverfe ftripes, their females may 

 be feen hovering over plants infefted with /Iphides, among which 

 they depofit their eggs, on the furface of the leaf. The larva, or 

 maggot, produced from fuch eggs feeds, as foon as hatched, on the 

 younger kinds of Aph'n\ and, as it increafes m fize, attacks and de- 

 vours thofe which are larger. Thefe larva are ufually of a pale 

 colour, adhere clofely to the leaf, along which they flowly glide, 

 and are formed very tapering towards the head. When fully 

 grown, they change to a pupa, or chryfalis, attached to the leaf, from 

 whence iffues the fly. The larva of thefe flies contribute their 

 full Ihare to diminilh the defpoilers of Flora. To thefe three kinds 

 of infetSts, which are the chief agents in the hands of Nature for 

 keeping the Aphides within their proper limits, we may add a few 

 others which aft a fubordinate part in this neceflary bufmefs of 

 deftruftion. 



The larva of the Hemerobius feeds on them in the fame manner 

 as that of the Mufca aphtdivora, and depofits its eggs alfo on the 

 leaves of fuch plants as are befet with Aphides. The eggs of this 

 Hemerohiui (land on long filaments, which are attached by a bafe to 

 the leaf, and have more the appearance of the filaments of flowers 

 with their anthera: than the eggs of an animal. The number of 



thefe 



