INSECT ENEMIES OF WESTERN FORESTS 85 



the season they are about 1 inch long-. These immature larvae 

 spend the first winter hibernating in clusters at the base of the 

 needles. They resume feeding the following spring, and the cater- 

 pillars reach full growth by the last of June. When mature, they 

 crawl down the trees and enter the soil to a depth of 1 to 5 inches, 

 where they form elliptical cells, sometimes sparsely lined with a 

 silky material, in which they transform to the pupal stage. The 

 pupae are dark reddish brown, from 1 to iy 2 inches long, and 

 about y 2 inch wide. The pupal stage lasts a full year, and the moths 

 are not ready to emerge until the following June and July. 



An interesting sidelight on the economic importance of this in- 

 sect is that the larvae or pupae form a delectable food for certain 

 Indian tribes. The Mono Indians of California dig trenches around 

 the infested trees and build smudge fires, which cause the cater- 

 pillars to drop to the ground in great numbers. They are caught 

 in the trenches, killed, dried, and eaten cooked with vegetables to 

 make a stew. The Klamath Indians in Oregon prefer the pupae, 

 which, when dug from the ground and roasted or boiled, are con- 

 sidered a great delicacy. 



Epidemics of the pandora moth are brought under control by a 

 number of natural enemies. Probably the most important is a wilt 

 disease that attacks them about the time they reach full growth 

 and start to descend the trees. Once this disease becomes well es- 

 tablished it runs rampant through the hordes of caterpillars, and 

 very few of the insects escape. Ground squirrels and chipmunks 

 dig up and destroy large quantities of pupae. Birds feed only spar- 

 ingly on the caterpillars, which appear to be distasteful to most of 

 them. Four or more species of insect parasites attack the cater- 

 pillars and dispose of many of them. 



Now that DDT is available, this defoliator probably could be 

 held in check by airplane spraying in the early spring immediately 

 following resumption of larval feeding. 



Light burning is a method of control that was tried by a private 

 timber company on a large tract of privately owned land in south- 

 ern Oregon. In the fall of 1922 fire was run through this tract 

 while the pandora caterpillars were feeding. The smoke and heat 

 caused them to drop to the ground, where they were destroyed. On 

 account of the damage and danger in the use of fire, this method 

 is of questionable benefit. The remedy may easily be "worse than 

 the disease." 



A closely related species, Coloradia doris Barnes, first described 

 in 1900 from Colorado, became epidemic in 1938-39 on ponderosa 

 pine near Osage, Wyo., and on the Harney National Forest in 

 South Dakota. It also has been reported from Montana. The large 

 caterpillars have long, branched spines on the first and second 

 dorsal segments behind the head and on the last abdominal seg- 

 ment, as contrasted with pandora larvae which have short, stout 

 spines on all segments. The adults have wings much less heavily 

 scaled than pandora with the hind wings translucent and the 

 discal spots oblong instead of round and not so prominent as in 

 pandora. 



