[57] COLLECTING AND PEESERVING INSECTS EILEY- 



of tbe species is very essential to success. From immature galls no- 

 rearings need be expected. A good plan is to examine the galls from 

 time to time and collect them when it is found 

 that the larviie are beginning to abandon them. 

 In the case of species like the common Cone Gall- 

 gnat of the Willow, the larvse of which do not 

 leave the gall to undergo transformation in the 

 earth, it is advisable not to gather the galls 

 until the transformation to the pux)a state takes 

 place, which, in this species, occurs in early fig. si.— a Syrphus-fly. 

 spring. The various leaf-mining and seed-inhabiting species can be 

 treated as in the case of the Microlepidoptera. 



COLLECTING ORTHOPTERA. 



The insects of this order may all be collected by the use of the sweep- 

 ing net. Some of the families are attracted to light, as certain of the 

 roaches and green locusts, or Katydids {Locustid(e). Our common 

 roaches {Blattidce) are cosmopolitan insects, and infest dwellings. 

 Certain species are also found about ponds, under rotten logs, the bark of 

 trees, and particularly in decaying vegetable matter. In the tropics the 

 species are very abundant, but aside from the domestic forms, they 

 occur rarely in northern latitudes. The collection of the egg-cases- 

 (ootheca) is important as they furnish many interesting characters. 

 TheMantidfe, of which the Preying Mantis f Phasmomantis Carolina) is. 



Fig. 82.— a blind Cricket (Hadenalcus) from Mammotli Cave. (From Packard.) 



t 



a type, are sluggish, carnivorous insects frequently found about houses 

 and may best be collected by general sweeping of vegetation. The 

 Phasmidie or Walking-sticks are herbivorous and may be collected in the 

 midst of vegetation by sweeping or by the hand. The crickets {Gryl- 

 lid(e) frequent, for the most part, moist situations. Certain forms, like 

 the Mole-cricket and the Jumping Water-crickets {Trydactylus spp.), 

 burrow in moist soil and occur in numbers near the edges of ponds and 

 water courses. The katydids and locusts are abundant on low shrubs 

 or trees and in pasture and meadow land, but are most numerous in 

 the somewhat dry, arid regions of the West. Most of these insects 



