240 



INSECTS INILRIOL'S TO VEGETABLES 



distribution extends from ocean to ocean, and it is appareiillv 

 more abundant on the Pacific coast than eastward. 



Remedies. — The tortoise Ijcetles which prey upon sweet 



Fig 156.— Black-legged tortoise beet'e. a, Larvae, natural size; b, larva divested of 

 pack of excrement; ■.-, pupa. Both enlarged. (After Riley) 



])otato are r.ot as a rule of <;reat economic importance. The 

 remedies prescribed below for the sweet-potato flea-beetle are 

 about all that are usually required. 



The Sweet-potato Flea-beetle {Chcctocncma confiin's Lee). — 

 In ])arts of the United States, notably in New Jersey and Mary- 

 land, this insect causes considerable injury to the sweet potato 

 by eating out channels along the veins on both surfaces of the 

 leaves soon after the plants are set out. This gives the leaves 

 the appearance of having been attacked by a leaf-miner. Soon 

 after attack on young plants, the entire surface becomes seared. 

 When the insect occurs in numbers leaves are destroyed and 

 plants are killed outright. Attack is most severe on ground 

 previously grown in sweet potato, and also follows the clear- 

 ing of fields which have been allowed to grow in bindweed, one 

 of the insect's natural food plants. 



Remedy. — Plants before setting out should be dipped in a 

 strong solution of arsenate of lead, and one or two sprayings 

 of the leaves with arscnicals a week or two later is about all 

 that is needed, because the plants, being hardy, easily recuperate 

 from attack and suffer little injury other than that of defolia- 



