346 



ELEMENTARY ENTOMOLOGY 



although some entomologists spread the wings on both sides. The 

 front margins of the hind pair of wings should be at right angles 

 to the body, the front pair being brought forward until they just 

 touch the hind pair. 



Platyptera. White ants are usually mounted in alcohol, or on 

 microscope slides, although the winged forms may be pinned 

 through the metathorax. The wings are seldom spread. Book- 

 lice are mounted either on points 

 or on microscope slides, while 

 bird-lice are invariably mounted 

 on microscope slides. Earwigs 

 are mounted on points, or, in the 

 larger forms, the pin is inserted 

 through the anterior portion of 

 the right wing-cover. 



Orthoptera (Fig. 481). In the 

 FIG. 481. Showing method of pinning or dinary grasshopper, and in 



Orthoptera / / 



those torms having the prono- 



(After Washburn) 



turn well developed, the pin is 



usually inserted through the posterior margin of the pronotum. 

 In forms in which the pronotum is not well developed the pin is 

 run through the metathorax. The wings may or may not be 

 spread, but the usual method is to spread the wings on the right 

 side of the body. Care should be taken to arrange the legs and 

 antennae, the latter being laid back over the body, 

 if possible. The legs may be held in position by 

 running the pin through a square of stiff paper, 

 which is brought up to the proper distance and 

 the legs kept in a natural position until dry. 



Hemiptera (Fig. 482). All of the larger He- 

 miptera are pinned through the metathorax ; the 

 smaller forms, with the exception of the Aphididas FlG ' 48 f Sh g 



method ot pinning 



Hemiptera 

 (After Washburn) 



and scale insects, are mounted on points. The tw 7 o 

 latter groups require special methods of mounting. 

 The Aphididae are frequently mounted by plac- 

 ing them on a glass slide and covering them with a drop of Canada 

 balsam dissolved in xylol. They are allowed to stand for twenty- 

 four hours, when a small amount of fresh balsam is applied, and 



