6 INSECTS INJURIOUS TO FOREST AND SHADE TREES. 
and also of fruit trees, such as the pearand apple. According to Riley 
(First Report, p. 24), the larvee are frequently found at great depth, 
sometimes as much as ten feet below the surface. It has been claimed 
by Miss Margaretta H. Morris, in an account published in 1846, that 
pear trees have been killed by the larvie sucking the roots. This has 
been denied by the late Dr. Smith of Baltimore, who says: 
The larva obtains its food from the small vegetable radicals that everywhere per- 
vade the fertile earth. It takes its food from the surface of these roots, consisting of 
the moist exudation (like animal perspiration), for which purpose its rostrum or snout 
is provided with three exceedingly delicate capillaries or hairs, which project from 
the tube of the snout and sweep over the surface, gathering up the minute drops of 
moisture. This is its only food. The mode of taking it can be seen by a good glass.— 
Prairie Farmer, December, 1851. 
Mr. Riley adds that Dr. Hall, of Alton, Ill., has often found them firmly 
attached to different roots by the legs, but never found the beaks in- 
serted. He remarks as follows: 
The fact that they will rise from land which has been cleaned of timber, cultivated, 
and even built upon for over a dozen years, certainly contravenes Miss Morris’s state- 
ment, while their long subterranean existence precludes the necessity of rapid suc- 
tion. Itis also quite certain that if they thus killed trees we should oftener hear of 
it, and I have captured a gigantic but unnamed species of Cicada on the plains of Col- 
orado, 50 miles from any tree other than a few scattering willows. 
We would add that in June, in Idaho Territory, we have seen numer- 
ous Cicadie which had just appeared above the surface of the earth in a 
desert region with scattered sage bushes, upon whose roots, which it 
is known descend to a great depth, the young may feed. While, then, 
the Cicada may seldom do marked injury to the oak, the reader is re- 
ferred to page 35 for a further notice of the injury done by this insect 
to the twigs and smaller branches of the oak and other trees. 
_In Europe the roots of oaks are affected by a small wingless gall-fly, 
which punctures the root and inserts an egg into the hole. The irrita- 
tion thus set up causes the root to swell until a tumor or gall is formed, 
in the center of which lies the white footless larva or maggot of the fly. 
Fitch has found similar wingless flies in this country, but they will 
always remain objects rather of a scientific than economic interest. He 
has described them under the names of Biorhiza nigra, Cynips (Philo- 
nix) fulvicollis and nigricollis. They are wingless, and occur in forests 
in November and December, often walking on the snow in company 
with other snow insects, such as Boreus and Chionea. 
AFFECTING THE TRUNK. 
1. THE LOCUST CARPENTER MOTH. 
Xyleutes robinie Harris. 
Order LEPIDOPTERA; Family BOMBYCID®. 
Boring large holes and galleries in the trunk ; a large livid reddish caterpillar, nearly 
three inches long, greenish beneath, and the head shining black; the body somewhat 
flattened, and with scattered long fine hairs. The chrysalis also in the burrow, and 
transforming to a large thick-bodied moth in June and July. 
In different parts of New England, from Maine to Rhode Island, and 
