New York AGRICULTURAL EXPERIMENT STATION, 243 
SUMMARY OF LIFE HISTORY. 
The periodical cicada lives in the ground during most of its 
life. The seventeenth year in the north and the thirteenth year 
in the south pup appear above ground. The winged adults 
escape in a few hours. Their life is short, probably varying from 
about two to three weeks. Eggs are laid in the twigs of decidu- 
ous trees, shrubs and vines. They hatch in six or seven weeks. 
The young drop to the ground and work their way into the 
soil. They feed upon the sap from the roots, which they secure 
by inserting their beaks into the bark. They probably move 
but little, but live in a cell of earth just large enough to accom- 
modate their bodies. The larval and nearly all the pupal life is 
passed in the ground. Slight injury may be caused by sucking 
the sap from the roots, but the principal injury results from 
depositing the eggs in the twigs. 
BROODS. 
Two distinct races— Two distinct races of the periodical 
cicada are known, the seventeen and the thirteen-year races. 
The former is confined to northern temperatures and requires 
seventeen years to complete the life cycle, while the latter is 
confined to the south and requires but thirteen years. 
Number of broods and distribution — The number of broods 
was originally placed by Dr. Riley at twenty-two. Later investi- 
gations by Marlatt" resulted in his placing the number at 
thirty and renumbering all of the broods. The distribution is 
evidently confined to the United States east of the Rocky 
Mountains where the cicadas have been found in varying abund- 
ance in every State except Maine and New Hampshire. 
An interesting table has been prepared by Marlatt giving the 
old and proposed enumerations of the broods. Of this table 
Mr. Marlatt! says: “The following table, beginning with 1893, 
-when the initial broods of both the seventeen-year and thirteen- 
year series appeared in conjunction, illustrates the new nomen- 
clature suggested, and in parallel columns also are given the 
1U, 8. Dept. Agr., Div. Ent , Bul. 18, n. s., p. 53. 
"U.S. Dept. Agr, Div Ent., Bul. 18, n.s., p. 54. 
