INSECT ENEMIES OF WESTERN FORESTS 



123 



black. The larvae are rather stout, soft bodied, humpbacked grubs. 

 In western forests the alder flea beetle is probably the most com- 

 mon representative of this family. 



No control appears practical or warranted under forest condi- 

 tions, but on park and shade trees leaf beetles can be controlled 

 by spraying with powdered acid lead arsenate, 4 pounds to 100 

 gallons of water, as soon as the leaves unfold in the spring. 



Figure 55. — Alder flea beetle (Altica ambiens) : A, Adult beetle, X 4; 

 B, eggs, X 4; C, larva, X 4; D, pupa, X 4;£, skeletonized leaf. 



The alder flea beetle (Altica ambiens (Lee.)) (fig. 55) is a na- 

 tive species found throughout the Pacific Coast States, where it 

 feeds on and skeletonizes the foliage of alder, poplar, and willow, 

 both as larvae and as adults. The adults are small, dark shiny blue, 

 and about % inch long. The mature larvae are a trifle over % 

 inch long, dull brown to black, with shining black head and thorax 

 and three pairs of short legs. The adults hibernate during the 

 winter in debris beneath the trees and other sheltered places, 

 appearing early in the spring to resume feeding. Clusters of yel- 

 low eggs are deposited sometime after the spring appearance of 

 the adults. The larvae, which appear a few days later, reach ma- 

 turity in August, and pupate on the ground in the duff. New adults 



