INSECTS INJURIOUS TO THE SWEET POTATO 431 



brassy-brown, about one-sixteenth inch long, thick set, and the 

 wing-covers when seen under a lens are deeply striated. 



Life History. -The beetles hibernate over wint2r in rubbish, 

 under logs, leaves or other vegetation, and emerge early in May. 

 They mate as soon as they have fed a little, and disappear by the 

 middle of June in New Jersey. But little is known of the early 

 stages of the insect and they have never been found on sweet- 

 potato plants. The larvae have been found, however, feeding on 

 the roots of bindweed. The larva (Fig. 308) is a slender, white 

 grub, about one-eighth inch long, and feeds externally upon 



FIG. 309. Sweet-potato leaves injured by the sweet-potato flea-beetle. (After 



J. B. Smith.) 



the smaller roots. The beetles appear again in August, but do 

 not as a rule feed on sweet potatoes, preferring bindweeds and 

 wild morning-glories, from which they disappear in late September. 

 Control. By dipping the plants in arsenate of lead 1 pound to 

 10 gallons of water, as they are being set, they will be protected 

 and any beetles feeding on them will be killed. The plants should 

 be allowed to dry slightly before being set. Dipping the plants 

 is much better than spraying them later, as it is practically 

 impossible to completely cover the plant by spraying, as may be 

 done in dipping, which is much quicker and less expensive. Late- 



