12 



BULLETIN 418^ V. S, DEPARTMENT OF AGRICULTUEE. 



Table 4 shows strikingly the damage that ordinary surface fires 

 have done to the yellow-pine timber in several instances in various 

 parts of Oregon: 



Table 4. — Damage done by surface fires to merchantable yellow pine over 12 inches in 



diameter. 



[Average of 156 sample acres distributed over four typical fresh bums in Oregon.] 



Locality. 



Percentage by number of 

 trees in each class. 



Appar- 

 ently un- 

 injured. 



Burned 

 to death. 



Felled 

 by fire. 1 



Scarred 

 bjflre.^ 





3.2 



2.7 



0.8 

 6.8 

 3.2 

 2.3 



31.9 

 43.2 

 46.9 

 45.5 



64.1 





50 



Big MiTiam River fire 1910, Wallowa National Forest 



49.9 





49.5 







1 The figures in this column would be fully twice as large if the percentage by volume of the trees that 

 were killed, instead of the number, were taken, since it is chiefly the larger trees that are felled by fire. 



2 This column includes also trees that were scarred by previous fires, since it is impossible to distinguish 

 those scarred in the last fire from those previously injured. 



3 On these burns the trees which were actually killed by the intense heat of the fire were not distin- 

 guished fr cm those killed by being felled by the fire eating out basal fire scars. 



SOURCES OF INJURY OTHER THAN FIRE. 



INSECTS.i 



Next to fire, insects are the most destructive enemies of yellow 

 pine. Hardly a square mile can be found in the State in which there 

 is not fresh evidence of insect damage to the living timber. There 

 are many insects, chiefly boring grubs, that work in dead or dying 

 yellow-pine trees and in yellow-pine lumber, but relatively few that 

 attack the Hving tree. In Oregon there are but three species 

 important enough to interest the forester and timberland owner; 

 one of them is a defoUator and the others are bark beetles. The 

 defoliator is the '' pine butterfly " (Neophasia menapia], a small white 

 moth, winch, when in the caterpillar farm (the caterpillars are black, 

 with bright green markings, and are about IJ inches long at maturity), 

 feeds upon the needles of yellow pine. Sometimes the fohage on a 

 tree is almost all eaten off and the tree suffers severe damage or, if 

 the defohation is repeated, death. This insect is found to some 

 extent in various parts of Oregon, but so far as known it is not now 

 doing any great amount c^ damage. There have been a number of 

 serious infestations of the insect elsewhere, notably in Yakima and 

 Chelan Counties, Washington, where yellow-pine timber over a con- 

 siderable area was killed. It is a pest which is decidedly dangerous 

 when it becomes abundant. 



There are a large number of species of bark beetles which are more 

 or less harmful to living yellow pine, but only two of them are par- 

 ticidarly important in Oregon, the western pine destroyer {Demdroc- 



1 See Department of Agriculture, Bureau of Entomology, Bulletins 32; 38, pt. 2; and 83, pt. 1 ; and Circulars 

 125, 126, 127, and 129, for full description of these insects. 



