DISEASES AKD EHEMIES OP THE SWEET POTATO. 51 



Others describe the " black rot" as the rotting ofi 

 of the sprouts from, the potato in the beds, or showing an 

 occasional sprout with black spots on the otherwise white 

 stem and roots. It is regarded as a capricious disease, 

 depending upon the weather and other causes. 



Ants often undermine plants in the ridges or hills, 

 and do some mischief, as do cut-worms. The remedy is 

 frequent hoeing. The striped-bug is sometimes trouble- 

 some. This is easily managed by sowing air-slacked 

 lime on the vines. There are also small, whitish-yellow, 

 mealy insects called "peddlers," that feed on the leaves, 

 they work entirely upon the under side of the leaves, 

 and seldom do much harm. Dusting with Paris green 

 when the leaves are wet or damp, it is supposed, would 

 put them to rout. 



Just here the Sweet Potato has the advantage of most 

 other plants, and, especially of the common or Irish po- 

 tato. In fact, it has two advantages over that tuber. It 

 is seldom molested by bugs or worms, and it will grow 

 and thrive in warm, dry soils, where the common potato 

 would wither and perish for want of coolness and mois- 

 ture. 



No insect, so far, has troubled the Sweet Potato to 

 damage it to any extent. If the bugs continue to de- 

 stroy the common potato, as in years past, we will have 

 to turn our attention more to the growing of the Sweet 

 Potato to fill its place. [While Virginia is fortunate in 

 being free from*the insects that injure the Sweet Potato 

 vine, farther West, especially in Missouri, they are at- 

 tacked by several species of Tortoise Beetles, mostly of 

 the genus Cassida. The larva is armed with numerous 

 spines, and has the unpleasant habit of covering its back 

 with a shield of its own excrement. The perfect insects, 

 which also feed on the vines, have the wing covers and 

 thorax so extended as to give them a strong resemblance 

 to a miniature tortoise 5 some of them are exceedingly 



