55 MISC. PUBLICATION 273, U. S. DEPT. OP" AGRICULTURE 



Two years, are required for this insect to complete its life cycle. 

 Adults appear during the latter part of June and in July, and the 

 females deposit eggs that hatch in August. The young larvae crawl 

 up the trees and during the early molts feed in groups on the new 

 foliage. At the end of the season they are about 1 inch in length. 

 The first winter is spent by these immature larvae hibernating in 

 clusters at the base of the needles. Feeding is resumed in the follow- 

 ing spring, and the caterpillars 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, some- 

 times sparsely lined Avith a silky material, in which they transform 

 to the pupal stage. The pupae are dark reddish brown and from 

 1 to 11/2 inches in length and about one-half inch in width. The 

 pupal stage lasts a full year, and the moths are not ready to emerge 

 until the following June and July. 



An interesting side light 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 subsequent!}^ cooked with vege- 

 tables to make a stew. The Klamath Indians in Oregon prefer 

 the pupae, which, when dug from the ground and roasted or boiled, 

 are considered 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 at about the time they reach full growth 

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

 lished 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 sparingly 

 on the caterpillars, which appear to be distasteful to most of them. 

 Four or more species of insect parasites attack the caterpillars and 

 dispose of a large number. 



This defoliator could be held in check by spraying or dusting 

 trees with arsenicals during the spring period of maximum feeding, 

 provided such insecticides could be applied at a reasonable cost. 

 Airplane dusting is about the only way in which such poisons could 

 be applied to large forested areas, and because of the cost it is ques- 

 tionable to Avhat extent such a method could be used. 



Another method of control which was tried by a private timber 

 company on a large tract of privately owned land in southern 

 Oregon is light burning. 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, wdiere they were de- 

 stroyed. On account of the damage and danger which may ensue 

 in the use of fire, this method is of questionable benefit. The remedy 

 may easily be "worse than the disease." 



TIGER MOTHS 



(Arctiidae) 



The tiger moths are so named on account of the contrasting colors 

 shown by many. Some of the species are without markings, but 

 the majority are unusually beautiful. The caterpillars are robust 



