250 



THE FORESTER. 



October, 



assistants more profitably by cutting only 

 mature trees and effectually disposing of 

 the lopings, without disturbing the well- 

 mulched surface which is so essential. 



When forest trees are removed, if man 

 will assist just a little, reforestation will 

 be speedy and complete, for the surface is 

 rich. But after repeated fires it is more 

 difficult. The soil that has been building 

 for one or two hundred years, is nearly or 

 quite gone, and the rains run off rapidly, 

 while the sun and wind dry up the surface. 



The plan to build storage reservoirs, as 

 advocated by the National Irrigation As- 

 sociation, is most commendable and should 

 receive the support of every friend of 

 forestry. At the same time let us put our 

 natural reservoirs in repair. The rainfall 



on our mountains will average 48 inches 

 annually, and if our mountains are well 

 clothed, at least one-half will be retained 

 by percolation. With our 4,500 square 

 miles of watershed in southern California, 

 we would have 2,800,000 acre feet of 

 water for irrigation. Then would our 

 country be productive and bloom as the 

 rose, and be capable of sustaining a greater 

 population than the same area in any part 

 of the world. 



And what is true of southern California 

 is true of all the western arid and semi- 

 arid portion of the country ; capable, 

 when the forest and irrigation plans are 

 perfected, of sustaining a greater popula- 

 tion than now exists in our nation. Stop 

 fires, plant trees, and build reservoirs. 



INSECT ENEMIES OF FORESTS AND FOREST PRODUCTS. 



By A. D. Hopkins, 

 Entomologist, West Virginia Agricultural Experiment Station. 



THE problem of insect enemies of 

 forests and forest product, is be- 

 coming one of special interest and 

 importance to consider in connection with 

 other problems relating to the introduction 

 and practical application of scientific meth- 

 ods of forest management. 



The evidence obtained by the writer 

 from special investigations along this line 

 during recent years, is conclusive that 

 the losses resulting from the depredations 

 of insect enemies of living' forest trees are 

 very great. This is true both as related 

 to the direct causes of death of trees, and 

 of the pin and worm hole defects in the 

 standing timber, and the manufactured 

 product. 



Some of the most striking examples of 

 these insects and their ravages may be 

 briefly mentioned as follows: the destruc- 

 tive pine bark beetle,* which in 1S91-1S93 



was so vastly destructive to the pine and 

 spruce forests of the middle Alleghanies. 

 The chestnut timber worm* is the most 

 destructive enemy of the wood of the old 

 living chestnut trees throughout the Ap- 

 palachian region. The oak timber wormf 

 is not only destructive to the wood of liv- 

 ing trees, but also heavy oak lumber and 

 timbers in mill yards and in structures 

 under conditions which favor a continued 

 moist condition of the wood. The de- 

 structive heart wood borersj infest and are 

 destructive to the wood of living trees in- 

 jured by fire and other causes. Other 

 wood-boring insects breed in the wood of 

 old dead trees, stumps, logs, railroad ties, 

 and other heavy construction material after 

 it becomes old and begins to deteriorate. 

 The spruce-destroying beetle of the 

 northeastern spruce region is another ex- 



'' Dendroctonus frontalis destructor Zimrn 

 Hopk. 



*Lymcxylon sericeum Harr. 

 ^Eupsalis minuta Drury. 

 %Cerambycid and Buprestid beetles. 

 Dendrodonus piceaperda Hopk. 



