4 INSECTS INJURIOUS TO FOREST AND SHADE TREES. 
_a moderate amount of information upon the subject at the present time 
will attract the notice of the public and lead owners of land to pay a 
little attention to the subject and do something towards checking the 
ravages of noxious insects. 
In France and Germany private persons, entomologists such as Per- 
ris in France, and especially Ratzeburg in Germany, have published 
beautifully illustrated general works of very great interest and value 
upon forest insects, and their works have done immense service in those 
countries, where an enlightened government and an intelligent people 
have felt the importance of building up schools of forestry and of 
making laws compelling due efforts towards repressing the more injuri- 
ous forest insects. 
Kaltenbach, in his work entitled ‘Die Pflanzenfeinde aus der Klasse 
der Insekten,” or the Insect-enemies of Plants, has enumerated, in a 
closely-printed volume of 848 pages, the species of insects preying upon 
the different trees and plants of all sorts of Central Europe. The num- 
ber of insects found upon some kinds of forest trees is astonishing, though 
it is to be remembered that all kinds are not equally destructive, the 
most injurious and deadly forms being comparatively few. 
Kaltenbach enumerates 537 species of insects injurious to the oak, 
and 107 obnoxious to the elm. The poplars afford a livelihood to 264 
kinds of insects; the willows yield food to 396 species ; the birches har- 
bor 270 species; the alder, 119; the beech, 154; the hazelnut, 97, and 
the hornbeam, 88. Coming to the coniferous trees, as the pine, spruce, 
larch, firs, etc., the junipers supply 33 species, while upon the pines, larch, 
spruce, and firs, collectively, prey 299 species of insects. In France 
Perris has observed over one hundred species either injurious to, or 
living upon without being especially injurious to, the maritime pine. 
These are described in an octavo volume of 532 pages, with numerous 
plates. 
The number as yet known to attack the different kinds of trees in the 
United States may be seen by reference to the following pages. It is 
sufficiently large to excite great fears for the future prosperity of our 
diminished forests, unless the government interposes, and through the 
proper channels fosters entomological research in this direction. Our for- 
ests, moreover, are much richer in species of trees than those of Europe. 
We have, without doubt, on the trees corresponding to those of Europe as 
many destructive species asin Europe. But we have many more shade and 
forest trees of importance in the Eastern United States alone, and when 
we add to these the forest trees of the Western Rocky Mountain pla- 
teau and of the Pacific coast, and when we look forward to the atten- 
tion which must be given in the immediate future to the planting of 
Shade and forest trees on the great plains and in California, the subject 
of forest entomology assumes still more importance. 
The author has here arranged the forest trees in the order of their 
importance, beginning with the hard-wood or deciduous trees, the oak 
