150 Cockroaches, Locusts, Grasshoppers, and Crickets 



The katydids arc rather large, almost always green insects that live in 

 trees and shrubs, where they feed upon the leaves and tender twigs, some- 

 times doing considerable injury. With almost all the other Locustids, 

 they will also take animal food if accessible, and some of the ground- 

 inhabiting forms undoubtedly depend largely on animal substances for 

 food. The color and form of the wing-covers and body serve to make them 

 nearly indistinguishable in the foliage, and as they do not flock together 

 in numbers, they are not frequently seen. Their love-calls or songs, how- 

 ever, make the welkin ring at night from 

 midsummer until the coming of frost. Few 

 katydids sing by day: it would bring their 

 enemies, the birds, down on them; but as 

 twilight approaches, the males begin their 

 shrilling, which is kept up almost constantly 

 till daylight. Like the sound-making Acri- 

 diids the musical Locustids have a pair of 

 special auditory organs, or ears, for hearing 

 these love-songs. These ears are tj-mpanal 

 organs situated one in the base of each fore 

 tibia (the Acridiid ears are on the upper 

 part of the first abdominal segment), and 

 consist of a thin place in the chitinized 

 l)(Kly-wall (the tympanum), a resonance- 

 chamber inside, and a special arrangement 

 of nerves and ganglia. There are several 

 genera of these Locustids, corresponding to 

 the distinctions popularly made under the 

 vernacular names narrow-winged, round- 

 winged, angular-winged, oblong leaf-winged, 

 and broad-winged katydids. The true 

 katydid is one of the last-named forms, 

 the commonest and most wide-spread species 

 being Crytophyllus concavus (Fig. 206). 

 It is bright dark-green, and is rarely 

 distinguished when at rest in the foliage, although familiar to all from its 

 shrill singing. When specimens of katydids are collected and examined, 

 concavus may be readily distinguished by the fact that its wings are shorter 

 than the wing-covers, and these latter are very convex and so curved around 

 the body that their edges meet above and below. The ovipositor of the 

 female is short, compressed, slightly curved and pointed. This katydid 

 is most in evidence in late summer. People disagree about the melody 

 and alleged charm of the song. Many cannot distinguish the "katydid" 



Fig. 200. — Broad-winged katydid, 

 Cyrlophylhts concavus, male. 

 (After Harris; natural size.) 



