PHASMIDAE 19 



PHASMIDAE. 



This family is very feebly represented in the United States, 

 only half a dozen different genera with from one to three species 

 each having been detected. These few species, however, repre- 

 sent three of the dozen recognized subfamilies. With the excep- 

 tion of Diapheromera which has a wide distribution, most of the 

 species are found only in the west or the extreme south. One 

 genus is confined to the United States. 



All of our species are apterous, and though, on occasion, the 

 males may run with some rapidity, they are all generally sluggish 

 in movement, and depend for their protection largely on then- 

 resemblance to twigs and on the action of their prothoracio 

 glands, which may emit an offensive fluid or spray when the 

 insect is alarmed. Their eggs are dropped loosely and singly on 

 the ground ; they are of very varied structure, covered with an 

 exceedingly hard and often strikingly sculptured shell, and so far 

 as we know continue through the winter, sometimes through a 

 second, before hatching. Our commonest species feeds upon the 

 tough leaves of the oak. 



Subfamilies of Phasmidae. 



A ^ Tibiae not furnished at apex with a sunken areola to receive 

 the base of the tarsi when bent upon them. (The antennae are 

 much longer than the anterior femora and furnished with at least 

 thirty joints, and the median segment is much shorter than the 

 metanotura.) ...... Hacunculinae. 



A ^. Tibiae furnished at apex beneath with a sunken areola to 

 receive the base of the tarsi when bent iipon them. 



6 1. Antennae many jointed, longer than the fore femora; 

 median segment shorter than the metanotum ; without spines 

 on head, thorax or legs ; anterior segments of abdomen trans- 

 verse, at least in the 9 . , . . Anisornorphinae. 

 h^. Antennae with less than twenty joints, shorter than the 

 fore femora ; anterior segments of abdomen much longer than 

 broad. ....... Bacillinae. 



