NOXIOUS 
OF THE 
STATE OF NEW ^ORK. 
By ASA FITCH, M. D. 
ENTOMOLOGIST OF THE NEW-YORK STATE AGRICULTURAL SOCIETY. 
Copy-right Secured to the Author. 
INSECTS INFESTING DECIDUOUS FOREST TREES. 
Such a multitude of worms and other insects as feed on the leaves and 
other parts of our deciduous forest trees, I find it will be impossible for me 
to fully comprise in a single Report. I therefore here present the more 
common and pernicious ones, with a few others which are less common 
but whose history has never before been published. The oaks being our 
most important trees of this class, and attacked by a far greater number of 
insects than any of our other forest trees, will claim a principal part of our 
present Report. 
1. TIIE OAKS .—Quercus alba, etc. 
AFFECTING THE ROOT. 
A disease to which the different kinds of oaks, in Europe, arc subject, 
and to a less extent the beech and other forest trees, shows itself in the 
form of small excrescences or galls about the size of ground nuts, which 
grow upon the slender thread-like roots of the trees. These excrescences 
are caused by a small insect which punctures the root and forces an egg 
into the opening. The irritation which this egg occasions causes an 
increased flow of sap to the part, whereby it swells and grows into one of 
these gall-nuts. In the center of each of these nuts lies a small white 
footless worm, which eventually changes into an insect of the gall-fly 
kind, but which differs remarkably from all the other insects of the group 
to which it pertains, in being wholly destitute of wings. It has lienee 
received the specific name aytera, and forms a distinct genus named 
Biorhiza by Mr. Westwood. I suppose this name to be derived, not from 
life, as its orthography would indicate, but from j3ta, injury, and 
pt^a, a root, and if so it should be written Biarhiza instead of as we find 
it in books. 
The roots of forest trees being so seldom exposed to our view, I know 
not whether similar excrescences occur upon them in this country. But it 
is quite probable that they do, since wingless gall-flies occur here, closely 
resembling that of Europe. I have repeatedly met with these in forests, 
' 
ON THE 
AND OTHER INSECTS 
