SMALL, ACTIVE FLEA-BEETLES INJURING FOLIAGE 161 
The Sweet Potato Flea-beetle (Chetocnema confinis Cr.) 
Soon after sweet potato plants are set in the field they begin to show 
the characteristic work of the sweet potato flea-beetle. Narrow lines 
are gouged out on the surface of the leaf, at first following parallel 
to the veins, but later running 
in any direction. At the 
same time the beetles them- 
selves will be noticed in in- 
creasing numbers. They are 
tiny, active, bronze-colored 
Fig. 172.—The Sweet Potato 
Flea-beetle. Enlarged and nat- 
ural size. Original. 
insects, one sixteenth of an 
inch long. 
In three or four weeks the 
beetles practically all disap- 
pear, having migrated to wild 
plants of related species. The 
Fic. 171.— Work of the Sweet Potato Flea- 
beetle. Original. only injury is at the beginning 
of the season. 
Dip the plants in arsenate of lead when setting them out, immersing 
the tops but not the roots. Use 1 pound of lead arsenate to 8 or 
10 gallons of water. In addition, spray the plants with arsenate 
of lead about ten days later, to protect new foliage. Plants that are 
set out late will escape serious injury. 
