150 SAWFLIES, ICHNEUMON-FLIES, WASPS, ETC. 



The first division, that of the Sawflies [Tenthrcdi- 

 nidcB), is exceedingly hurtful to various crops and trees, 

 by the ravage of its caterpillars to the leaves, or in 

 some cases to the fruit; also, in some cases, by causing 

 Galls. The second division, the Sirexes {Uroceridie) y 

 feeds for the most part, if not entirely, in the cater- 

 pillar state, in timber. A third, that of the Gallflies 

 (Cynijndce) , inserts its eggs in various parts of plants, 

 thereby giving rise to variously formed gall growths. 

 on leaf or inflorescence, shoot, or stem, or root, of 

 which the bunch of moss-like growth on the wild rose 

 shoots, commonly known as the "Eobin's pincushion," 

 and the Marble-gall of the oak, may be taken as ex- 

 amples of most different forms. 



A vast number of difterent kinds of insects of this 

 order, commonly known as " Parasite Flies," and be- 

 longing to thefamilies of the Ichneumonidce, Chalcididie,. 

 and Proctotrupid^e, help us by inserting their eggs into 

 other insects, in which the parasite grubs feed quietly 

 on the living material, until their hosts sink beneath 

 the task of supporting their unwelcome guests. 



Besides these families, which concern us much 

 agriculturally, there is a large division, including 

 difterent kinds of Ants, Bees, and Wasps, known by 

 reason of most of them possessing a sting, as the 

 division of Acnlcata* 



We need just to observe what the general appear- 

 ance of the insects of this order is in each of the three 

 stages ; but the families which I wish chiefly to be 

 noticed are those of the Sawflies, which are very in- 

 jurious, and the Parasite-flies, which are very helpful 

 to us. 



We may know the insects of this order, in a general 

 way, by their likeness to common Wasps or Bees. 

 They have two pairs of membranous wings ; a mouth, 

 sometimes furnished with short and thick, or with long 

 and narrow, pincer-like jaws {mandibles), as in Wasp& 



* From Acii!^, a needle. 



