LOCUSTS, SHORT-HORNED GRASSHOPPERS, ''GRASS- 
HOPPERS"— Family ACRIDIDAE. 
The members of this family are characterized by relatively 
short antennae, usually shorter than the body or body and wings; 
tarsi usually of but three joints (in one subfamily reduced to two 
except on the posterior pair) ; hearing organs on the sides of the 
basal segment of the abdomen; and stridulating rasps (when 
present) on the inner side of the hind thighs or the external sur- 
face of the wing-covers. The antennae are thread-like, some- 
times considerably enlarged and prismatic at base, or slightly 
enlarged and flattened at tip. 
Anatomy, Habits, etc. — An excellent guide to the anatomy of a 
member of this family is "The Anatomy of the Carolina Locust," 
by Robert E. Snodgrass, published by the Washington Agricul- 
tural College and School of Science, Pullman, Washington (State) 
(1903, 50 pp., 6 pis.). This I have used freely in the earlier 
pages. It treats of both external and internal anatomy and his- 
tology, and is well illustrated. Comstock's "Elements of Insect 
Anatomy," well known to every Cornell student of entomology,, 
contains a chapter on the anatomy of the Red-legged Locust, but 
lacks illustrations. A popular account of the same subject, with 
sketches, by Professor MaryA. Willcox, appeared in the Observer, 
for May, 1896, and brief directions for study in the number for 
July following. The three volumes of Reports of the United 
States Entomological Commission on the Rocky Mountain 
Locust, etc., 1878-1883, contain a wealth of information on many 
topics relating to this species and to migratory Locusts in general, 
their habits, enemies, rnethods of extermination, etc. Two 
papers giving more recent methods are the following: "Grass- 
hopper Control" (Farmers' Bulletin, U. S. Dept. Agric, no. 747, 
20 pp., 1916) ; "Efficiency and Economy in Grasshopper Control," 
by E. D. Ball (Journ. Econ. Ent., vol. 10, p. 135-138, 1917). 
Their general anatomy and habits have been treated at length 
in the preceding chapters and need not be further dwelt on here. 
Details of structure, habits, and distribution are stated in the 
keys for identification and under the specific headings. 
423 
