ORTHOPTERA. 97 



recurrence should be guarded against by burning the leaves upon 

 the ground under the infested trees in the autumn, thus destroying 

 the eggs. 



Family V. — Acrididae.* 

 {Locusts or Short-horned Grasshoppers.) 



The Acrididae and the two following families constitute the sec- 

 tion Saltatoria or Jumpers. The members of this section agree in 

 having the hind legs fitted for jumping, by being either very much 

 stouter or very much longer, or both stouter and longer, than the 

 femora of the other legs. The females are usually furnished with a 

 prominent ovipositor, and the wings of the immature forms are in 

 an inverted position. 



In many species, especially of the Acrididae, the adult is fur- 

 nished with rudimentary wings ; and thus presents the appearance of 

 an immature form. But by means of the character just given it is 

 easy to distinguish the adult even in the case of these short-winged 

 species; for in the immature forms the tegmina are folded beneath 

 the wings, and the principal veins of both tegmina and wings curve 

 downward instead of upward. 



The family Acrididce includes the Locusts or Short-horned Grass- 

 hoppers. These are common and well-known insects. They differ 

 from other Saltatoria in having the antennae much shorter than the 

 body, and consisting of not more than twenty-five segments. The 

 ovipositor of the female is short, and composed of four separate 

 plates, and the basal segment of the abdomen is furnished on each 

 side with a supposed organ of hearing. 



The head is usually short, although in two of the sub-families it is 

 extended horizontally. Immediately under the vertex, but in some 

 cases above it, there is on each side a little space bounded by ele- 

 vated ridges. These spaces are termed the lateral foveolce ; their 

 variations in form afford characters which are much used in classifi- 

 cation. The front is generally traversed by three vertical keels or 

 carina ; the one on the middle line is termed the median carina 

 or frontal cost 'a, the others are the lateral carina. The pronotum 

 is divided into four lobes by three more or less well-marked trans- 

 verse sutures; it is also often furnished with a median crest. The 

 hind tibiae carry upon the upper side two rows of spines: the num- 



* Acrididae, Acrldium: acridion (aKuidiuv), a small locust. 



