100 MISC. PUBLICATION 273, U.S. DEPT. OF AGRICULTURE 



plane spraying (90) offers the only practical means of controlling 

 this defoliator on large forest areas at a reasonable cost. Applica- 

 tion of 1 pound of DDT in a gallon of fuel oil per acre is very 

 effective in destroying young caterpillars as they travel to the tops 

 of the trees to feed. It should be applied after the eggs have 

 hatched, preferably from the middle of June to mid-July. 



Figure 41. — The oak looper {Lambdina fiscellaria somniaria) : A, Cater- 

 pillars on defoliated branch; B, pupae; C, adult moths, female above, 

 male below. Slightly enlarged. 



The oak looper (Lambdina fiscellaria somniaria Hulst) (fig. 41) 

 represents a race of loopers so closely related to the hemlock 

 looper as to be scarcely distinguishable. This race shows a dis- 

 tinct preference for Oregon white oak, on which it feeds in 

 Oregon and northward into British Columbia. Other trees may 

 be attacked, but usually only when intermingled with the pre- 

 ferred host tree. In some seasons the oaks over large areas in 

 Willamette Valley, Oreg., are completely defoliated by this species. 

 No permanent damage is done, however, since the oaks are able 

 to leaf out again the following year. 



