73 



Hydrometridae — Water-measurers ; not injurious. 

 Reduviidae — Rapaceous bugs, and hence beneficial. 

 Cimicidae — Bed-bugs. Noxious. 



Capsldae Lygaeidae Corlsidae and Scutelleridae — Families containing 

 most of the injurious species of the sub-order. 



Thripidae — Thrips — Minute insects found in flowers and other ten- 

 der parts of plants. 



DIPTERA. 



This order contains a vast number of species, which have been ar- 

 ranged very differently by different authors. I shall mention only a 

 few of the principal families. 



Cidicidae — The mosquitoes and gnats. 



Cecidomyidae — The gall-gnats, including the wheat-fly, Hessian-fly, 

 and other injurious species. 



Tipulidse — The long-legged gnats. 



Pullcidss — The fleas. 



Simididse — Black gnats. 



Tabanidse — Horse-flies and golden eyed forest-flies. 



Asilidx— Robber-flies ; large, rapacious flies. 



Syrphidas — Syrphus-flies ; very beneficial. 



(Eestridm — Bot-flies and breeze-flies. 



Muscidse — House-flies, flesh-flies, blue-bottle Hies, &c. 



Hlppoboscidx — Forest-flies and sheep-ticks. 



In order to assist the unscientific reader as far as possible in his 

 effort to find, by means of this report, any insect mentioned, I will 

 illustrate here the method of determining the Order to which any 

 perfect insect belongs, which is the first step in determining the 

 .species. 



Suppose he finds a species very abundant which he suspects is con- 

 nected with certain larva? which have been very injurious to a partic- 

 ular plant. Examining its mouth he finds it has biting jaws, it is 

 evident from what has been already stated that it belongs either to 

 the Coleoptera, Hymenoptera, Neuroptera, or Orthoptera, as these are the 

 only orders which have biting jaws. The upper wings are hard and 

 horny, and the under wings are thin and membranous, and folded, 

 both lengthwise and crosswise. By examining the characters of the 

 mandibulate orders, as already given, he finds it must belong to 

 Coleoptera, as this is the only order with biting jaws which has wings 

 of this character. If the upper wings are leathery or parchment-like, 

 and the under wings membranous, and folded lengthwise like a fan, 

 it must belong to Orthoptera. Suppose it has four wings, all of which 

 are thin and membranous, and that it has biting jaws; it must belong 

 either to Hymenoptera or Neuroptera; if it has a sting this shows at once 

 that it belongs to the former; if the wings arc all equal size, and 

 crossed by numerous veins, and it has no sting, it is a species of the 

 latter order. 



If it has a sucking mouth it must belong^ either to Lepidoptera, 

 Hemiptera, or Diptera, and the mouth and wing characters given will 

 readily determine to which of these it appertains. 



