208 LEAF-MINING INSECTS 



very actively. If disturbed they will sometimes drop to 

 the ground and feign death. This is one of the least un- 

 common and most widely distributed of our weevil miners. 

 It ranges from Nova Scotia to Quebec through New England 

 to Oregon and south to Texas. It has been taken on willows 

 and shad bush and found mining the leaves of elm, alder, 

 cherry and apple. 



This weevil is single-brooded. The adults spend the 

 winter among leaves and grass, under clods, or in cracks in 

 the soil. When the frost has left the ground in the spring 

 they become active and ascend to the branches of the trees. 

 As the leaves appear they feed on them and soon begin 

 depositing their eggs. The female gnaws out a longitudinal 

 cavity in the under side of one of the major leaf veins. Mov- 

 ing the ovipositor over this hole she deposits in it a smooth, 

 yellowish, bluntly rounded egg. This process is repeated 

 at intervals for about a month. The wound made by the 

 female in depositing the egg produces a slight swelling and 

 a subsequent bend in the vein. 



The eggs hatch in four or five days. In feeding the larvae 

 at first make linear mines winding towards the edge and 

 usually towards the tip of the leaves. There, changing their 

 method of feeding, they gnaw out a blotched portion which 

 becomes somewhat inflated. The mines become brick-red 

 in color and are then quite conspicuous. 



The larvae are somewhat depressed, yellow in color, and 

 when fully grown are about three-sixteenths of an inch in 

 length. They are broader near the head and after the sixth 

 segment generally decrease in width. The last segment is 

 very narrow and ends in a rather acute point. 



The larvae feed in the leaves for about three weeks. They 

 then construct rounded cocoons in the inflated portion of 

 their mines. After a brief period as soft white pupae they 

 transform to beetles and gnaw their way out. (See fig. 57, 5.) 



The first beetles of a new generation begin to appear 



