KOKKST WANAGKMENT. Gl 



tlic 8nl])linr leaf-roller motli (IHcltclid sulphin-rana Clem.), 'J'enis fcmit/oiia S. V., ini<l Amnrlna 

 luimcrosdiKt i^\iin\. An iiiteresliiiin' species is tlio piiio tube, \miU\vi- i l.opliofltrioi polilniia Haw.), 

 wliicli, iu its liirval stage, lives witiiin a tube Ibriued by webbing together a number of jiiiui needles 

 as shown in fig. 14. 



A number of species of adult Coleoptera, whose larval habits are, iiiiperfe(!tly understood, sub- 

 sist upon the lea\es of White Pine. Of these are the Scarabieid, JHchelonycha albivollis Burin., 

 and the Chrysomelid, (lli/pldxcclis pubcsccns F.nh. 



The best remedy for the sawfly larvie, caterpillars, and beetles is a spray of J'aris green, 

 applied u[)on the first appearance of tiieso insects on the trees. 



The consideration of the insect enemies of tlie White Pino may conclude with the mention of 

 the pine-leaf scale insect {Uliionaspis pinifoUw Fitch), which forms its scales upon the leaves, 

 exhausting them of their juices and causing them to turn yellow. This species is illustrated at 

 fig. 15. 



A strong si)ray of kerosene emulsion will be found an efficieut remedy against these scale 

 iusects. 



FOREST MANAGEMENT. 



As regards forest management, we have, unfortunately, in this country no experiences which 

 would i)ermit us to form very positive opinions based on actual observation regarding this si)ecies 

 or any other. The stiuly of the natural history of the species in its native occurrence permits us, 

 nevertheless, to draw conclusions which may at least serve as a basis for its future sylvicultural 

 treatment. 



In the first place, it may be declared that theAVhitc Pine is the most imjjortant and i)ronusing 

 species upon which to expend aitention in our coming forestry operations within tiie limits of its 

 natui-al occurrence. Its ada})tation to a variety of soils and situations within these limits, its rapid 

 growth, its excellent form, its remarkable mass development per acre, its shade endurance, its 

 all-round useful wood product, and its propagation, both by natural and artificial reproduction, 

 give it a position among our timber trees hardly approached by any other. 



There are certain general princi])les which are the result of experience in forest management 

 iu lOurope and elsewhere, applying to this as to most species. The lirst is, that mixed growth is in 

 every respect superior to pure growth; it will therefore bo proper policy to grow White Pine pref- 

 erably, if not altogether, in mixture with other species. This advice is given in spite of the fact 

 that the White Pine grows rather well in pure stand, and that, owing to its shady crown during a 

 long i)eriod of its life and the <lensity of stand in which it can develop, and the large ([uantity of 

 foliage which it sheds, the soil conditions are not in danger of deteriorating, as would be the case 

 with more light-needing species. But, as has been observed in its natural occurrence, its develop- 

 ment is more favorable in companionship, and especially is this the case witli regard to the 

 cleaning of the bole of its branches, which are peculiarly persistent. Whether it would pay to 

 substitute an artiticiaP cleaning by pruning the young growths is still doubtful; meanwhile the 

 self-pruning performed by nuxture with shady companions will have to be encouraged, especially 

 as thereby other valuable advantages are secured which attach to the mixed forest in general. 



Unfortunately, our irrational exi)loitation has reduced the White Pine in the natural forest areas 

 often to such an extent that its reestablishment is possible only by artificial means. Wherever 

 the culling has not been too severe, and either young growth has developed or seedling trees have 

 been left, the natural reproduction should be encouraged by favoring the young growth and by 

 removing or thinning out other species which interfere with the starting of a young growth. 

 Fortunately, the White I'ine, owing to its shade endurance, is specially fitted for natural lepro- 

 duction from the seed of mother trees, more so than most other pines, and the rai)idity of its 

 growth, in which it excels most other shade-enduring species, is also favorable iu this respect. 



We are not yet prepared to determine the most profitable rotation iu which the species is to 

 be managed under varying conditions. The fact that it is not only a \ery rapid but oiw of the 

 most i)ersistent growers, trees making wood at the rate of li to 2 cubic feet per year up to the 

 one hundred and fortieth year, permits a wide range of choice for I'otations, and since its wood, 

 being rapidly changed into heartwood, becomes serviceable very early, the rotations maybe either 

 low or high, varying from fifty to one hundred and fifty years, according to local economic and 

 soil conditions. 



