

TORTOISE BEETLES AND " GOLDEN BUGS " 249 



The Rhubarb Flea Beetle. This greenish flea beetle (Psyl- 

 liodes punctulata Mels.) exhibits a preference for rhubarb, but it 

 is also found on other vegetables. Its presence is recognized 

 either by holes in the leaves or by brownish-yellow spots on the 

 leaves. When necessary, one may resort to the usual remedies 

 for flea beetles. (See page 228.) 



INSECTS AFFECTING SWEET POTATOES 



The sweet potato in most districts is quite free from insect 

 attacks, as compared to many other truck crops. The sweet 

 potato borer is perhaps the most injurious of the eight or ten 

 pests which are found attacking these plants. 



The Sweet Potato Root-borer or Weevil. This snout beetle 

 (Cylas formicarius Oliv.) is known to occur in China, India, 

 Australia, Madagascar, Jamaica, and Cuba. It was probably 

 first imported into this country from Cuba hi shipments into 

 Louisiana. 



It is a slender beetle, one-quarter of an inch long. It some- 

 what resembles an ant. The general color is bluish black, with the 

 pro-thorax brown. 



Injury. The female eats cavities into the potatoes or into the 

 vine at its base and deposits its eggs therein. The young larvae 

 at first bore into the vine and later into the tubers. The pupal 

 stage is passed within the tuber. Evidently this insect may con- 

 tinue to increase and cause injury even after the potatoes are 

 stored. 



Control. No treatment is available while tubers are in the 

 ground. Badly infested potatoes may be fed to hogs and the vines 

 burned. Growers who receive potatoes from infested localities 

 should fumigate them before planting. Use either bisulfid of 

 carbon or hydrocyanic acid gas. (See page 61.) 



Tortoise Beetles and "Golden Bugs." Several species of these 

 insects, members of the family Cassidce, are fond of the foliage of 

 the sweet potato. Of these, a very common form is the golden 

 tortoise beetle (Coptocycla bicolor Fab.), the common name of 

 which indicates its color. The black-legged tortoise beetle (Cassida 

 nigripes Oliv.), however, is the largest of this group and the most 

 injurious. The mottled tortoise beetle (Coptocycla signifer Feb.) 

 is another member of this family affecting the sweet potato. 

 Another is the two-striped sweet potato beetle (Cassida bivitata 

 Say). 



