REVIEWS 819 



to the sprout hardwood region, while north and south of this section 

 the same valley is placed in the white-pine region. As yet broad belts 

 on the western and northern sides of New England are free of the gipsy 

 moth. The common trees (75 species selected) are divided into four 

 classes, depending on the degree to which their foliage is favored as 

 food by the gipsy moth larvae. This list, the discussion following, and 

 the recommendations at the end of Part I, should be studied carefully 

 by woodland owners in the infested territory with the purpose of select- 

 ing the proper species to favor in forest management. 



The purpose of Part II is "to co-ordinate the results of the food- 

 plant experiments with known principles of forest management and 

 with economic conditions in the infested region, to see how far we may 

 reasonably expect to rely upon forest management to control the moth." 

 Management must be based largely upon the susceptibility of the stand 

 to gipsy moth attack. 



Munro finds that out of the 75 tree species listed in Part I, only 18 

 are what may be termed "controlling trees," so far as management is 

 concerned. Six representative sample plots in Massachusetts, Maine, 

 and New Hampshire are described in detail, and recommendations for 

 management according to one, two, or three different plans are laid 

 •down for each plot. This is the. most valuable part of the bulletin for 

 the average woodland owner. 



In general, for stands containing a large proportion of favored food 

 plants, removal of the stand in one or two cuttings, planting of conifers 

 or immune hardwoods like white ash, with several cleanings, is advised. 

 Where the proportion of favored food plants is small, cuttings to re- 

 move these species without subsequent planting may be sufficient. In 

 some stands a special "gipsy-moth cutting" must be made. Under cer- 

 tain natural and economic conditions the selection system should be 

 used. In his conclusions on the possibility of overcoming the moths 

 by forest management Munro says : "Each lot and each combination of 

 species presents a problem in which the controlling factors are site, 

 soil, location, market, species present, their value and relative propor- 

 tion, the degree of infestation, and the cost of labor. In many cases 

 these factors combine in such a way that management is economically 

 impossible." Apparently as much, if not more, assistance may be ex- 

 pected from the wilt disease and parasites as from forest management 

 in controlling the gipsy moth. There seems reason to believe that 

 eventually the moth will be reduced to a normal place among other in- 

 jurious insects. A li<;t of hteralure on the subject will be found in the 

 appendix. R. C. H. 



