24 CIRCULAR 639, U. §. DEPARTMENT OF AGRICULTURE 
The eg@ (fig. 24), which is about one-sixtieth of an inch long, is 
oval and pearly white. Itis deposited by the female beetle on or near 
the surface of the soil in cracks and crevices. If the tobacco has 
been newly set the eggs are usually laid in the moist depressions at the 
base of the stalk where the plant is watered at setting time. Later 
in the season, when the plants are larger, most of the eggs seem to 
be deposited some little distance away from the stalk, beneath the 
lower leaves resting on the ground. A study of overwintered females 
under caged conditions indi- 
cates that they may deposit at 
least 200 eggs each. In the 
early spring months the eggs 
hatch in about 11 days, whereas 
in the summer they usually 
hatch in about 5 days. The 
moisture content of the soil in- 
fluences the hatching of the flea 
beetles’ eggs to a marked extent. 
Eggs placed by the beetle upon 
air- “dry soil fail to hatch, and a 
comparatively low hatch occurs 
if the eggs are placed on soil 
that is only slightly moistened. 
The egg hatches into a small 
whitish caterpillar, or larva 
of an inch long. When first 
Figure 24.—Eggs of the tobacco flea hatched these larvae begin an 
beetle, about X 20. active search for food. The 
natural food of the larva is the 
small fibrous rootlets of the tobacco plant and other plants of the 
family Solanaceae. The young larvae frequently tunnel into the roots, 
whereas the older larvae usually gnaw completely through them. As 
the small roots may be completely severed from the plants, the larvae 
probably do considerable damage when they occur in large numbers. 
During the cool weather of early spring the larval period. lasts about 
29 days, but in the hot weather of midsummer this time is shortened 
by nearly one-half. When full-grown the larva attains a length of 
approximately three-sixteenths of an inch 
(fig. 26). 
The pupa, or resting stage, is passed 1n 
a small oval-shaped cell just below the 
surface of the soil. In this stage (fig. 27) Freure 25.—Newly hatched 
the insect more nearly resembles the adult — 12"va_of the tobacco flea 
form, the legs, antennae, and wings being ieee 
plainly seen “folded under or about the body. In the spring this stage 
requires about 714 days, but in the summer it may be reduced to 4% 
days. The pupa ‘then changes to the adult, or beetle. 
The adult of the tobacco flea beetle (fig 28) is rather small, measur- 
ing only about one-sixteenth of an inch in length. It is brown with 
two darker areas of rather indefinite size and shape on the wing covers. 
The adults frequently emerge after showers, which moisten “the sur- 
face soil and aid their exit. Heavy driving rains are, however, 
(fig. 25), about one-thirtieth | 
