1 6 TETTIGID.^E OF NORTH AMERICA 



allied genera an unusual diversity of coloring and polymor- 

 phism exists. Polyandry occurs in most if not all the species 

 and in Tettix the number of different males received by one 

 female may be considerable, as shown in the experimental 

 evidence. (See experiments further on.) 



SEXUAL HABITS. 



When the male sights the female he walks with a hurried, 

 tremulous gait, or sometimes it is jerky. Stealing nearer, he 

 runs up close, climbing on her back from the side. Some- 

 times in his e.xcitement he faces temporarily in a reversed 

 position while on her back. The males seem to recognize 

 each other and though they may climb on each others' backs, 

 they seem to appreciate the sex, yet the sexes resemble 

 each other with the exception of size, the female being 

 considerably the larger. As shown by experimental observa- 

 tions, copulation lasts from a few seconds to several minutes. 

 In Tettix there is no anatomical provision for clasping the 

 female permanently, so that the male and female cannot go 

 about together for long periods, as occurs in the genus Tctti- 

 gidca and some other genera. At the sight of another species 

 or an uncongenial male the female usually shakes her body. 

 The author saw a female Tettix gibbosus recognize a male one 

 and a half inches away, and she made her aversion known in 

 the way above mentioned. After sexual conjugation the 

 ovipositor is made to open and close repeatedly to favor the 

 entrance of the male secretion. 



In Tettigidea parvipentiis ihe male jumps on the female's 

 back, riding about in this position until she becomes quiet. 

 At the same time he watches for the opportunity of effecting 

 conjugation. In his excitement he begins to lengthen out 

 the abdomen preparatory to emission. The appendages 

 undergo a jerking motion, then suddenly his hind legs 

 straighten out behind in a convulsive orgasm over her body, 

 the appendages now becoming moistened. Immediately 

 reviving, he backs a little, keeping, however, his forelegs 

 grasping her body. With his abdomen extended and reaching 



