118 OUTLINES OF ENTOMOLOGY. 



transparent membrane, which are supposed to be the seat of the sense 

 of hearing. The bodies of the males terminate in conspicuous stylets 

 or claspers, while those of the females bear a large sickle-shaped or 

 sword-like ovipositor, composed of two thin blades, by means of which 

 the eggs are inserted into bark or leaves, or are laid in over-lapping 

 rows on thin stems or on the edges of leaves. 



The true Katydid f Gyrtophyllus concavusj is the most robust-looking 

 species, the wing- covers being oblong and very convex on the sides, 

 almost meeting below as well as on the back. The taborets consist of 

 mica-like plates, with very strong, peculiarly curving ridges. The 

 Angular-winged Katydid ( Micro centrum retinervis) has longer, narrower 

 and less convex wings. The taborets are opaque, and the sounds pro- 

 duced resemble a metallic clicking sound, which has not been reduced 

 by any imaginative listener to syllables. The Narrow- winged Katydid 

 fPhaneroptera curvicaudaj is a smaller, duller-green species, with a less 

 noticeable note. It must be remembered that the males are the musi- 

 cians of the family, although the females are capable of emitting a faint 

 response by a sudden upward jerk of the wings. 



Among the Grasshoppers are some long, slender, bright-green 

 species which have the front of the head produced into a point. These 

 are called the Cone-heads. Xiphidium ensifer is the largest species. 

 The males produce the most deafening, continuous "whirr" of any of 

 the tribe. The females have a long, straight, sword-shaped ovipositor, 

 and in both sexes the wings are nearly twice the length of the body. 

 The smaller and very graceful Orchilimums, which enliven the autumn 

 days with their soft purring notes, belong also in this group. 



The true Locusts (Acrid^dje) are the species which live on grass, 

 grains and other low-growing vegetation, and are in this country very 

 generally called " grasshoppers." In this group belong not only the 

 various dull-green and brown species that are so numerous every year 

 in fields and pastures, and which in dry seasons become very injurious, 

 but certain migratory species, which, having exhausted the food supply 

 of the regions to which they are indigenous, by a common impulse rise 

 into the air in clouds and sweep like a besom of destruction over the 

 country. They fly by day and descend at night to feed, often traversing 

 thousands of miles before reaching their limit. These are the only 

 insects which have been used to any great extent as food, and this 

 mainly in trans- Atlantic countries, where the famishing inhabitants of 

 the desolated regions were forced to feed upon them or perish. The 

 Eocky Mountain Locust fCaloptenus spretus, Thom.) is the most im- 

 portant American species of migratory locust ; but one or two Eastern 

 species manifest a like tendency, and during some years prove very 

 destructive over limited areas. 



