830 NEW YORK STATE MUSEUM 
Shade tree insects (nos. 252-67). This group, illustrated by 19% 
Species, naturally comes very close to the preceding. It has 
been limited largely in the present instance to those species 
which are rarely of economic importance except when attacking 
shade trees; and, as these are among our most valuable assets, 
the group is of great economic importance. It includés such de- 
structive pests as the sugar maple borer, leopard moth, elm bark 
borer,elm bark louse, elm leaf beetle, white marked tussock moth, 
bag worm, and others, all very injurious to highly prized shade 
trees. Most of them can be controlled without excessive expense. 
For detailed accounts of these pests the reader is referred to the 
New York state museum bulletins 20 and 27, to the 12th report 
of the state entomologist and to his papers in the 4th and 5th 
reports of the fisheries, game and forest commissioners of New 
York. | 
Work of gall insects (nos. 268-97). This is a small collection 
of deformities produced in plants by 30 species of insects belong- 
ing to three different orders. It illustrates the effect a com- 
paratively insignificant insect may have on plant tissues, and in 
the study of the collection a number of interesting biologic 
problems are presented to the mind of the student. 
Systematic collection (nos. 298-931). This assemblage of 634 
species occupies nearly one third of the entire space devoted to 
the display of insects. It is arranged according to what are 
believed to be the natural affinities of the species. That is, the 
more closely related are put next to each other, so far as possible. 
There is nothing very new in the collection, but it accomplishes 
its object in giving the casual observer some idea of the immense 
number and variety of forms found in the insect world. Such 
a collection can make no pretense to completeness, as will be 
seen at once, when it is remembered that our best authorities 
estimate that between one and 10 million different species of 
insects now exist in the world. It has special value, however, 
to residents of New York state, since the more common native 
forms are very fully represented. This is of particular advantage 
in showing to some extent how many insects occur in a locality, 
