222 



A.V ECONOMIC ENTOMOLOGY. 



where they are rather abruptly terminated. The larvae are leaf- 

 miners, and perhaps the most common species is the Odojitota 

 dorsalis, or locust-beetle, which occurs abundantly on the leaves 

 in early summer, and is orange in color, with a broad black 

 stripe on the centre of each elytron. The eggs are covered with 

 a little mass of excrement, and are laid singly, few leaves con- 

 taining more than two or three. Not much real injury is done 

 by any of the species, and the suggestion that the adults feed 

 exposed and succumb readily to the arsenites is all that is neces- 

 sary on the subject of remedies. 



The adult Cassidce are called "tortoise-beetles," or, by the 

 sweet-potato grower, ' ' golden bugs. ' ' They are characterized 

 by their broad, almost quadrate form, flat under and convex 

 upper side, and by the moTe or less metallic-yellow or golden 

 color of the elytra and upper surface generally. Most of the 

 species feed upon Convolvulus^ to which natural family the sweet- 

 potato belongs, and the 

 latter is about the only cul- 

 tivated crop suffering from 

 the attacks of insects of this 

 series. The beetles hiber- 

 nate and appear in the sweet- 

 potato fields as soon as the 

 crop is set out, eating irreg- 

 ular holes in the leaves, and 

 laying their eggs, encased in 

 a mass of excrement, on the 

 under surface. The larvae 

 are known as "peddlers," 

 because they have piled 

 upon a pair of anal forks all 

 the cast skins and a part of 

 their excrement, forming a 

 sort of shelter, umbrella, or 

 "pack," to which latter 

 resemblance they owe the 

 common name. The most abundant form is the Cassida bivittata, 

 or "two-striped tortoise-beetle," so named from the two black 

 stripes on each wing-cover. Following closely is the Coptocyda 



Coptocycla aurichaicea. — a, larvse, or ped- 

 dlers, with their packs; b, larva with pack 

 removed ; c, pupa. 



