292 Phylum Arthr op oda 



THE GROUSE LOCUSTS* 

 Robert K. Nabours, Kansas State College 



THE grouse locusts, so-called probably because of a fanciful re- 

 semblance of some of them to the grouse (Tetraoninae), are among 

 the smaller Orthoptera. They show conspicuous dimorphism as to 

 length of wings and pronotum, with occasional intermediates. There 

 are extraordinary variations in the conspicuous color patterns on the 

 pronota, the legs, and other parts of the body. The stripes along the 

 median pronota vary in color and width, and there are many kinds of 

 spots, specks, mottlings, and all-over colors. One species, as Paratettix 

 texanus, may exhibit nearly all the colors and patterns. Food, light, and 

 other features of the environment do not appear to condition the colors 

 and patterns in any special way. (Hancock, 1902 ; Nabours, 1925 and 

 1929.) 



The subfamily Tetriginae is widely distributed over the tropics and 

 temperate zones. Hancock (1902) estimated that there were more 

 than 100 species in North America alone. They mainly inhabit moist 

 areas, along the margins of ponds and streams, and in forests, though 

 they may live, temporarily at least, in quite dry places. Some, as 

 P. texanus and A. eurycephalus in southern Texas and Mexico, are 

 found more abundantly along the flat, algae-covered margins of ponds 

 and streams, in the absence of larger vegetation and much exposed to 

 the sun. Others, as Tettigidea lateralis, are found farther back in the 

 grasses, or higher vegetation, where there is more shade. 



The northern grouse locusts (roughly from the line of the Ohio, 

 lower Missouri and Kansas rivers in the U. S. A.) probably produce 

 one, or an average of about one and one-half generations a year. The 

 cold weather coming on in October, or November, finds both adults and 

 nymphs, and they all go into hibernation for the winter. They stop in 

 tufts of grass, under stones, pieces of wood, etc., but receive little real 

 protection from the weather. They have been observed to endure and 

 survive a temperature lower than o° F. However, there is usually a 

 high mortality, due probably as much to desiccation as to cold. There 

 is no regularity about their going into, or emerging from, hibernation. 

 They do not become inactive till the cold weather actually arrives, and 

 they become active during any very warm periods. During aberrantly 

 early warm weather they emerge from hibernation, to be driven back 

 later in the spring if there is more cold weather. 



When warm weather arrives in the spring the adults mate and soon 



♦Pending a much needed, comprehensive revision of this subfamily by taxonomists, 

 I have undertaken to follow Hancock's classification of the few species used in the 

 studies of inheritance. However, I now propose to follow A. N. Caudell's (Smith. Inst.) 

 suggestion, in a letter, 1932, of subfamily Tetriginae; family Acrididac. 



