OUTLINES OF ENTOMOLOGY. • 119 



The Locusts are robust insects, stouter in body and legs than the 

 Grasshopper and Katydids, and are well protected by a firm leathery 

 integument. The head is even larger in proportion to the body than in 

 the preceding family. It is set vertically, in some species receding 

 toward the mouth. The eyes are large and broadly elliptical in form ; 

 antennj© short and rather thick ; the face is marked in many species by 

 three distinct ridges ; upper lip broad, with the lower edge somewhat 

 hollowed out just above the jaws. The saddle-like collar over the 

 back of the pro-thorax, or pro-notum, is marked by transverse in- 

 dented lines, and rounds out over the insertion of the wings. Many 

 locusts have on the pro-sternum, just under the chin, a cone-like pro- 

 jection sparsely covered with short spines or prickles. The wing 

 covers are of stout, closely netted membrane, with a projecting ridge 

 or heavy vein near the middle on the outside, or a series of prominent 

 veins on the under side. They are of a narrowly oblong form and 

 slightly overlap in a straight line on the back. The broad under wings 

 are so folded as to be entirely covered by them. The legs are 

 all stout, but the hinder pair, always much thicker, and gener- 

 ally much longer also, than the others, provide the leaping power 

 which is so wonderful in these insects. The outer margins of 

 Uie tibite are beset with a varying number of pairs of spines, 

 and just at the base of the three jointed tarsi are two pairs of 

 jointed spurs. At the base of the abdomen on each side is an 

 oval orifice covered with thin membrane, like those on the fore legs 

 of the Katydids, and, like them, termed the ears or aural sacs. 

 In the abdomen of the males nine segments can be perceived from the 

 under side. The anal appendages are a pair of side claspers and an 

 upward curving ventral plate. In the abdomen of the female but 

 eight segments can be distinguished, and the tip has four horny, 

 pointed blades, which can be brought together in a point to penetrate 

 the soil, and afterward spread out to pry the earth apart and prepare 

 a cavity for the reception of the eggs, which are extruded in a compact 

 mass, inclosed in a sort of glutinous pod or case. 



The stridulations of Locusts are effected in two ways by differing 

 species. Most of the larger species " fiddle," by rubbing the ridged 

 inner surface of the hind thighs over the prominent mid-vein of the out- 

 side of the wing covers. Prof. Comstock, quoting Mr. Scudder, who 

 has made most exact and interesting studies of the so-called musical 

 insects, says: "When about to stridulate they place themselves in a 

 horizontal position, with the head a little elevated; then they raise both 

 hind legs at once, and grating the femora against the outer surface of 

 the tegmina, produce notes which in the different species vary in rapid- 



