FOREST PLANTING IjST THE EASTERX UNITED STATES. 



19 



are likely to have one or more of the advantages cited. The prin- 

 cipal species in each mixture is named first; and where they take 

 i equal rank the fact is indicated by an asterisk (*) : 



1. Cottonwood and silver maple. 



2. Cottonwood and Norway spruce. 



3. Cottonwood and white spruce. 



4. Cottonwood and green ash. 



5. * European larch and white pine. 



6. * European larch and red oak. 



7. European larch and white spruce. 



8. * European larch and Norway spruce. 



9. "White pine and Scotch pine. 

 10. * White pine and Norway pine. 



11. White pine and hard maple. 



12. "White pine and red oak. 



13. Black walnut and white spruce. 



14. Old open stands of black walnut 



underplanted with white pine. 

 Many of the old groves, particularly in 

 Iowa, are of soft maple. These may be 

 gradually replaced by underplanting 

 with white spruce and removing the 

 maple. 



PROTECTION. 



INSECTS. 



The locust borer has completely destroyed rnan}^ plantations of 

 black locust; the white-pine weevil kills the leading shoot of white 

 pine; the gipsy and brown-tail moths defoliate the hardwoods, par- 

 ticularly the oaks, and in some cases have attacked conifers; while 

 the sawfTy has defoliated and killed much of the native larch and has 

 attacked also the European larch. Before setting out any trees the 

 prospective planter should communicate with the Bureau of Ento- 

 mology of the Department of Agriculture, or with the State experi- 

 ment station, in order to find out whether insect enemies of the species 

 he proposes to plant are prevalent in the neighborhood. At the first 

 sign of insects in an established plantation the owner should likewise 

 communicate with the Bureau of Entomology to ascertain the best 

 methods of combating them. 



FIELD MICE AND KABBITS. 



Young trees are sometimes girdled by field mice and rabbits. 

 Where these pests are numerous it is almost impossible to prevent 

 them from eating the bark of trees during the winter when green food 

 [of other kinds is absent. If the grass around the tree is killed by 

 cultivation there will be less danger from field mice, since these work 

 largely under the grass covering. Poisoning is not always an efficient 

 method of getting rid either of mice or rabbits; and poisoned food 

 mav kill some valuable domestic animal. 



WIND, SNOW, AND FROST. 



High winds often break or twist off the trees in a plantation. Such 

 damage may be avoided to some extent by planting wind-firm species 

 around the edge of the plantation, or by spacing the trees more closely 

 di\ the windward sides. 



