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After the last molt the animal is complete, and changes no more in size for the rest of its life. There has been an attempt among writers to restrict the term grasshopper to the long-winged, slender species, and to call the shorter winged, stouter species locusts according to old English usage.

Fig. 116.—Cockroach.

Fig. 117.—Praying Mantis, or devil's horse.

Fig. 118.—Cricket.

Economic Importance of Grasshoppers.—Great injury is often done to vegetation by grasshoppers; however, the millions of tiny but ravenous eaters hatched in early spring are usually soon thinned out by the birds. The migratory locusts constitute a plague when they appear, and they have done so since ancient times. The Rocky Mountain locusts flying eastward have darkened the sky, and where they settled to the earth ate almost every green thing. In 1874-5 they produced almost a famine in Kansas, Nebraska, and other Western states. The young hatched away from the mountains were not healthy, and died prematurely, and their devastations came to an end. Of course the migrations may occur again. Packard calculates that the farmers of the West lost $200,000,000 because of their ravages in 1874-5.

Fig. 119.—Mole Cricket.

Fig. 120.—Front Leg of Mole Cricket. × 3.