CONIFERiE. 



SILVA OF NORTH AMERICA. 



11 



88 Hohnel, Die Gerberinden, 15, 31, 45. — Neubrand, Die Gerb- 

 erinden, 219. — Watt, The Art of Leather Manufacture, 86. 



30 The planting of Pines and other Conifers for the production 

 of timber has been practiced in Japan for at least twelve hundred 

 years, and the wood used in the empire is nearly all obtained from 

 planted forests which cover sandy coast plains and other lands unfit 

 for the production of agricultural crops. 



40 The different North American Pines are infested by many 

 species of insects ; of these some are very destructive or are liable 

 to become so. It is probable that only a small part of the insects 

 affecting the trees of this genus in America are known. Packard 

 {Fifth Rep. U. S. Entomolog. Comm. 1890, 674) enumerates nearly 

 one hundred and fifty species found on Pine-trees in the United 

 States, and since the publication of his report the number has been 

 much increased. Borers in the trunk, branches, and bark make 

 about half the number of species which injure Pine-trees ; they are 

 chiefly coleopterous, those attacking the trunk belonging largely to 

 the family Cerambycidae and Buprestidae, while numerous Seolyti- 

 dae attack the sap wood and bark. Larvae of Monohammus confusor, 

 Kirby, Monohammus titillator, Fabricius, Monohammus scutellatus, Say, 

 and Monohammus marmoratus, Randall, are common in the trunks 

 of Pines over a large extent of country, the first-named species being 

 especially abundant. They sometimes do great damage, but usually 

 prefer to attack dead trees or those which are already injured or 

 diseased rather than perfectly healthy trunks. Asemum moestum, 

 Haldeman, Criocephalus agrestis, Kirby, and Rhagium lineatum, Oli- 

 vier, are sometimes destructive, however, to living trees. Larvae 

 of Callidium antennatum, Newman, and numerous other Ceramby- 

 cidae bore into the wood when dry. Among Buprestidae the larvae 

 of Chalcophora Virginiensis, Drury, often girdle the trunks and 

 cause their destruction, and other species of Chalcophora infest 

 them. Various species of Dicerca, Chrysobothris, Melanophila, 

 are often abundant and destructive to Pine-trees. The White 

 Pine weevil, Pissodes Strobi, Peck, is one of the worst pests of 

 young trees. The larvae live in the leading shoots or near the 

 tops of the central stems and cause them to wither and die, or 

 are found injuring the sapwood of older trees. Hylobius Pales, 

 Herbst, is another weevil common in Pines over a large part of 

 North America, and Pachylobius picivorus, Germar, is injurious in 

 the southern states. 



Among Scolytidae, Gnathotrichus materiarius, Fitch, Gnathotrichus 

 asperulus, Leconte, Xyloterus bivittatus, Mannheim, and various spe- 

 cies of Carphoborus bore under the bark or iu the sapwood. Den- 

 droctonus terebrans, Olivier, and other species of this genus, several 

 species of Xyleborus, Tomicus Pini, Say, Tomicus cacographus, 

 Leconte, Tomicus calligraphus, Germar, Hylurgops pinifex, Fitch, 

 species of Pityophthorus, Polygraphus, Crypturgus, and other 

 beetles bore in or under the bark. 



Among lepidopterous borers are several which injure the 

 branches or the bark and sapwood of Pine-trees. Bembicia Se- 

 quoias, H. Edwards, which bores into Sequoia, is said to seriously 

 affect also Pinus ponderosa and Pinus Lambertiana in California. 

 JEgeria Pinorum, Behrens, has been found in Pinus radiata in Cali- 

 fornia ; and Harmonia Pini, Kellicott, attacks the bark and sap- 

 wood of Pines in the middle states. The larva of a Pyralid, Ne- 

 phopteryx Zimmermanni, Grote, bores under the bark and in the 

 young wood of Pine-trees usually below the insertion of young 

 branches, and causes resinous exudations. 



The branchlets, especially of Pinus rigida and its allies, are 

 frequently affected by the larvae of small Tortricid moths chiefly 

 of the genus Retinia ; their attacks are often accompanied by 

 copious exudations of resinous juice and result in the death of the 



twigs, or by weakening them cause the leaves to turn yellow or 

 brown. 



The foliage of Pine-trees is injured in the United States by 

 many species of insects, although few of them are noticeably 

 destructive. Saw-flies of various species, chiefly belonging to the 

 genera Lophyrus and Lyda, are sometimes abundant and are likely 

 to cause considerable damage. 



Among Lepidoptera, the larvae of Pieris Menapia, Felder, is occa- 

 sionally extremely abundant on Pinus ponderosa, Pinus contorta, 

 and other species of the Pacific forests. 



Semiothisa bisignata, Walker, and other Geometridae, besides the 

 insects belonging to other groups, are found on various species 

 and occasionally cause considerable damage. 



Tortrix politana, Haworth, forms little tubes composed of the 

 living foliage of Pinus Strobus, and devours the outer ends of 

 the leaves which form the tube within which it lives. Gelechia 

 pinifoliella, Chambers, in its larval state mines the leaves of Pinus 

 rigida aud other species ; and the leaves of this tree and its allies 

 are also infested by a gall gnat, Diplosis Pini-rigidos, Packard. 



The leaves of young twigs are affected by many species of He- 

 miptera, among them spittle-insects, leaf-hoppers, aphids, and scale- 

 insects. 



Lachnus Strobi, Fitch, is common on the White Pine and often 

 destroys young trees ; and Lachnus australis, Ashmead, is found 

 on twigs of Pinus palustris and allied species in the southern 

 Atlantic states. A so-called "mealy-bug," Schizoneura pinicola, 

 Thomas, also attacks Pinus Strobus. 



Mytilaspis pinifolioz, Fitch, is an elongated white scale common 

 on the leaves of several species of Pines, and Chermes pinifolioz, 

 Fitch, and Chionaspis pinifolioz, Fitch, sometimes injure these trees. 



Several insects still little known often infest the cones of North 

 American Pines. 



41 The diseases of the different species of Pinus caused by fungi 

 are very numerous, and in Europe have been carefully studied with 

 regard to their pathological action. In the United States some of 

 the same diseases prevail, and there are also a large number of 

 native fungi which are parasitic on North American Pines, causing 

 them considerable injury. The rotting of the wood of Pines is 

 generally due to certain species of Polyporus and Trametes, which 

 attack Spruces and Firs as well, and also sometimes deciduous- 

 leaved trees. One of the most widely spread species is Trametes 

 Pini, Fries, a long-lived fungus of dark yellow-brown color which 

 appears in the form of small brackets on the branches and trunks 

 of Pinus sylvestris in Europe and the United States, on Pinus con- 

 torta, var. Murrayana, Pinus palustris, Pinus Strobus, and probably 

 other species. It produces the disease known in Germany as Ring- 

 schale, the mycelium extending up and down the trunk, especially 

 in the annual rings, and forming brown streaks and zones. Poly- 

 porus annosus, Fries, which in Europe is regarded as the most 

 destructive fungus to conifers, occurring there on Pinus sylvestris 

 and Pinus Strobus, has been recorded on the latter species in this 

 country, but not often, although it is probably more common than 

 has usually been supposed. It generally attacks the roots and 

 extends upward into the trunk. The mycelium causes the wood 

 to become red and rotten, and eventually forms dark-colored longi- 

 tudinal streaks and cavities. The fructifying part of this fungus 

 is generally found on or near the roots, and is usually resupinate, 

 with small white pores. Polyporus Schweinitzii, Fries, which is 

 apparently more common in the United States than in Europe, is 

 generally associated with Pinus Strobus. In Europe it produces 

 a disease of Pinus sylvestris, although in this country, in spite of its 

 frequency, it is not generally supposed to cause serious trouble. 



