.158 



Canadian Forestry Journal, November- December, 1912. 



\^oo(ls ail' ^eliioin coiii^istent, anil, while 

 they may serve to tell certain specimens 

 apart, they cannot be relied on in the ma- 

 jority of cases. This difficulty also applies 

 to deciiluous woods, but to a lesser degree, 

 as the individual peculiarities of a species 

 are usually more consistent with these woods. 

 Distinctions that rely on the difference in 

 color between heartwood and sapwood are 

 freely used, in s})ite of the fact that these 

 are useless with small hand specimens, in 

 the majority of cases. The writer attem}>ts 

 to distinguish between the woods of the 

 four Southern pines and of the different 

 species of sj)ruce, but explains that the dis- 

 tinctions are not always reliable. The gross 

 distinctions are not clearly distinguished 

 from the microscopic ones, and the pecu- 

 liarities in cross-sections are liable to be 

 confused with those of radial or longi- 

 tudinal sections. The identification key is 

 also accompanied by a complete list of re- 

 ferences to the existing literature. 



The book was designed for the iise of 

 foresters, timber inspectors and wood-users, 

 but would be of more value as an outline 

 of a course of study than as a handbook. It 

 is a trifle too technical for the average 

 wood-user, but should be invaluable to for- 

 estry students. 



A forest map of the United States and 

 a. series of thirty photo-micrographs of 

 characteristic wood sections is appended, 

 and the introduction contains a brief out- 

 line of the methods of preparing s])ecimens 

 for niicrobotanical study. 



The Larch Saw-fly. 



The Large Larch Saw-fly, the subject of 

 this bulletin*, is no doubt the most widely 

 known species of insect destructive to forests 

 in Canada, though of late years the Spruce 

 Budworm has come into prominence. Over 

 the whole of Eastern Canada this saw-fly has 

 lulled wellnight all the tamarack, or larch, 

 and of late its ravages have spread to the 

 middle western provinces of the Dominion. 



The Dominion Department of Agriculture 

 is fortunate in having in its emjiloy, as 

 Dominion Entomologist, in the person of 

 Dr. Hewitt, one who has given to the insect 

 an amount of study and careful investi- 

 gation such as no other student of entomol- 

 ogy has bestowed on it. The results of 



*Tlie Large Larch Saw-fly (Nematus 

 erichsonii) with an Account of its Parasites, 

 other Natural Enemies and Means of Con- 

 trol, hy C. Gordon Hewitt, D.Sc Dominion 

 Entomologist. {Dominion Department of 

 Agriculture, Experimental Farms. Bulletin 

 No. 10, second series: Entomological Bulle- 

 tin No. 5). Ottawa: Government Printing 

 Bureau, 1912. Pp. 42. One colored plate, 

 four half-tone illustrations and 22 figures 

 in the text. 



his investigations up to the present, both 

 in Kngland and Canada, are embodied in 

 this bulletin. The first part of the bulletin 

 is taken up with an account of the history 

 and distribution of the insect, the technical 

 description of it and an account of its 

 life-history. This is followed by a discus- 

 sion of the injury to trees (through oviposi- 

 tion by the mature insect and through de- 

 foliation by the larvae). A point of spe- 

 cial interest to foresters is that Dr. Hewitt 

 has found the saw-flies on the Japanese 

 larch (Larix leptolepis), generally supposed 

 to be immune. Natural enemies described 

 are field mice and birds. Special attention 

 is given to parasites and predaceous insects; 

 some twenty or more insect parasites and 

 one predaceous insect are described. The 

 study of Dr. Guessow, Dominion Botanist, 

 of the parasitic fungus Isaria farino.^o is 

 also outlined at some length. 



Much of the practical value of the l)ulle- 

 tin lies in the section on Preventive and 

 Remedial Measures. Constant vigilance, 

 care in planning a plantation (not planting 

 larch ' pure, ' i.e., as the only species in the 

 plantation) is urged, also the encouragement 

 and protection of birds. Remedial measures 

 for small plantations include spraying, de- 

 struction of cocoons, hand-picking, jarring 

 the trees and banding. 



The most hopeful means of restricting or 

 stopping the spread of the insect is the 

 aiding of the natural enemies of the insect 

 by fostering its natural parasitic enemies. 

 An outline of the work already done at 

 the Central Experimental Farm is given. A 

 short account of the economic value of the 

 larch is included in the bulletin, credit for 

 which is given to the Dominion Forestry 

 Branch. 



The author, Dr. Hewitt (Dominion Ento- 

 mologist, Central Experimental Farm, Ot- 

 tawa) will be glad to receive information 

 in regard to the insect. Copies of the 

 bulletin may be obtained by applying to 

 the Publications Branch, Department of 

 Agriculture, Ottawa. 



Dr. Schenk's 'Sylviculture.' 



Under the title of ' The Art of the Second 

 Growth, or American Sylviculture,' Dr. C. A. 

 Schenck, Director of the Biltmore Forest 

 School, has issued a revised (third) edition 

 of his * Biltmore Lectures on Sylviculture. ' 

 The form and arrangement of the work re- 

 main the same. As compared with the first 

 edition many emendations are to be noted, 

 and a number of changes in nomenclature, 

 e.g., ' sprout ' forest instead of ' coppice ' 

 forest, 'composite' instead of 'coppice un- 

 der standards, ' ' seed ' forest taking the 

 place of 'high' forest. The book is, as al- 

 ways, a handy manual of the art, and is 

 worthy of a place in every forester 's library. 



