The Bulletin. 55 



"before they have done much damage. The leaves seem to be able to 

 recover from slight injury, whereas if the larvae is allowed to continue 

 its work, the leaves never recover. If the leaves are covered with 

 either of the arsenates the larvae will secure enough poison before they 

 enter the leaf to kill them. After the larvae have once gained en- 

 trance to the leaf they will be apt to come out in order to make a fresh 

 blotch and will be killed by the poison when they are attempting to 

 gain entrance to the leaf. Arsenates for this insect should be used 

 at the strengths recommended for the Flea Beetle (page 35). 



The Margined Blister Beetle. 1 

 (Order Coleoptera.) 



This insect was found in the tobacco fields in several instances 

 severely ragging the leaves of the tobacco. In all instances it seemed 

 to have been forced to the tobacco for lack of food after having 

 stripped the leaves from common nightshade, which in this case 

 seemed to be the favorite food plant. 



Description. — The adult beetle (Fig. 

 43) which does the injury in this case 

 is a grayish-black beetle about % of an 

 inch long, with the edges of its wing 

 covers margined with light gray. It is 

 a chewing insect and strips the leaves 

 bare to the mid-rib. 



Life-history and Habits. — The life-his- 

 tory of the blister beetle is very inter- 

 esting because the larvae pass through 

 several stages and because they are 



Fig. 43.— Adult of the Margined Blis- £ •. «ffi„- i:^ 



ter Beetle, about natural size. enemies of grasshoppers. Ineir liie- 

 (Photograph by the author.) history may be summed up in a few 

 words: They deposit from July to October their orange or yel- 

 low colored eggs in irregular masses in loose ground, each fe- 

 male producing from four to five hundred eggs. In about 

 ten days these eggs hatch, producing very active, long-legged larvae 

 with large heads and strong jaws, which run about everywhere, 

 searching for the eggs of locusts. If an egg pod has been found, 

 the larva forces its way into it and commences to devour an egg; 

 if two larvae have found the same prize, a mortal combat takes 

 place, lasting until a single larva remains as sole owner of this store of 

 food. As soon as one or two eggs have been consumed the larva 

 throws off its skin and reappears in a very different shape, being 

 now white, soft, and possessing only small legs. In the course of 

 another week a second molt takes place, disclosing a larva with 



tEpicauta cinerea. 



