442 The American Naturalist. [May, 
ENTOMOLOGY.’ 
Shade Tree Insects.—Professor H. Garman’ publishes an excel- 
lent account of the pests of shade and ornamental trees. The article 
is chiefly concerned with insect pests, which are roughly divided into 
three groups: (1) Leaf insects, (2) trunk and branch mining insects, 
and (3) root infesting insects. To the first group belong the largest 
proportion of species, the walnut-worm, web-worm, elm leaf-bettle 
and others being included in it. “Such insects attract attention at 
once from the nature of their injury, the unsightly appearance due to 
gnawed leaves, webbing and refuse, taking away at once from trees 
their practical value as shade, and their esthetic value as ornament. 
“While their injuries are not at first so apparent, the work of the 
boring and mining species is not less injurious, and is the more to be 
feared because its results are not seen until the mischief under the bark 
is at an advanced stage. The locust borer and the elm bark-beetle are 
members of this group, both species being common and injurious in 
Kentucky. The pine bark-beetles and the fruit bark-beetles now be- 
coming injurious in this State may also be placed here. The greater 
number of species which attack the trunk are the grubs of beetles. A 
few are caterpillars (larvæ) of moths. The branches and twigs arè 
injured by a host of small species, some of which girdle them, others 
mine them, still other species do serious mischief by placing their eggs 
in them, while some of the true bugs simply puncture and abstract their 
p- 
“ Doubtless the number of insects which feed on the roots of shade 
trees is large, but the unavoidable difficulties in the way of studying 
their habits has prevented a very full knowledge of this group.” 
Mr. Garman treats of the life-histories of the species most destructive 
in Kentucky at some length. The bagworm is one of the first dis- 
cussed. This worm “lives in and carries about with it a case made of 
silk, on the outside of which it fastens bits of leaves, probably to render 
its detection less easy to birds and other enemies. One may se€ these 
cases all through the winter adhering to the naked twigs of both decidu- 
ous and evergreen trees, the worms having taken the precaution t0 fasten 
them there by wrapping the twigs with silk. The case of à g 
worm measures 1.75 inch in length and its greatest diameter 18 a 
‘Edited by Clarence M. Weed, New Hampshire College, Durham, N. H. 
* Bulletin No. 47, Kentucky Agr. Experiment Station. 
