Chapter V. 
INSECTS INJURIOUS TO THE DIFFERENT SPECIES OF MAPLE. 
(Acer saccharinam and Acer rubrum.) 
The number of species here recorded as infesting the different spe- 
cies of maple, especially the rock or sugar and the red or swamp maple, 
is upwards of one hundred. Of these only a few are really injurious. 
Of European insects preying on species of Acer, Kaltenbach enumerates 
sixty-eight species. The maple-borer, Glycobius speciosus, is the most 
deadly foe of these beautiful shade trees, and when once established on 
a street lined with maples, or in a grove, is difficult to eradicate. No 
caterpillar strips the leaves as a regular recurrent pest, but they are in 
the Central States often ruined by the cottony maple scale ; otherwise 
these trees are remarkably free from insect pests, and from their clean- 
ness and rapidity of growth, as well as dense foliage and beautiful out- 
lines, will always prove a favorite shade aud ornamental tree. 
1. The sugar-maple borer. 
Glycobius speciosus (Say). 
Boriug into the solid trunks of healthy sugar-maple trees, often killing them, a 
rather large, footless, cylindrical, whitish grub, changing in July to a large, beauti- 
ful, yellow-striped beetle, marked with a golden W ou the wing-covers. 
Although the question as to whether lougicorn larvaB will bore into 
healthy solid wood is by some regarded as undecided, there is no doubt 
but that the present larva bores for several inches into the trunks of 
healthy trees, both young maples as well as trees ten or twenty inches 
in diameter. The following case fell under our own observation. On 
the grounds of Bowdoin College, Brunswick, Me., for two successive 
years (1873-'74) a number of fine sugar or rock maples, nearly a foot in 
diameter, aud which had been set out for thirty or forty years, suddenly 
died, and on being cut up into fire- wood were found to be deeply per- 
forated in all directions by larvaB referable to this species by its large 
size aud resemblance to the locust-borer. More than one larva and one 
borer were found in the same tree. There seemed little reason to doubt 
but that the grubs were the cause of the sudden death of the tree. 
In the summer of 1881 I noticed that one tree in the college campus 
was partly killed by these borers, and that other trees in different 
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