STATE AGRICULTURAL SOCIETY. 
737 
PINK. TWIGS. 
The fluctuations which occur from time to time in the numbers 
of the plant-lice and the bark-lice are vory remarkable. Three 
and four years since these parasites abounded on almost every 
kind of tree and herb in my neighborhood. The pines were 
everywhere thronged with this species. The present summer I 
have searched in vain for a colony of these insects; and other 
vegetation appears to bo equally clean and free from vermin of 
this kind. 
In autumn winged individuals of this species having the third 
vein of their wings but once forked are so common that on some 
occasions nearly half the specimens I have gathered have prov¬ 
ed to be thus abnormal ; and I was hereby misled by the first 
specimens I examined, which, happening to be of this variety, 
induced me to regard this species as intermediate between and 
pai taking of the characters of both the genera Eriosoma and 
Lachnus, as stated in my description in the Catalogue of Ho* 
moptera in the State Cabinet of Natural History. 
In many instances it is extremely difficult to decide whether 
the Aphides of this country are or are not identical with those 
which occur upon similar vegetation in Europe. I entertain 
strong doubts with respect to the present species being distinct 
from the Lachnus Pini of Linnaeus. Heretofore, on carefully 
comparing specimens of these insects with the descriptions of 
L. Pini , given by Fonscolomb, Walker and others, I have some¬ 
times been confident they were different, and at other times 
have been equally confident they were the same. Different 
colonies appear to vary, and it may be that here, as in Europe, 
we have more than one species of Lachnus inhabiting the pines. 
An investigation more extended and thorough than I have yet 
had an opportunity to give these insects is necessary to settle 
these doubts. 
257- Parallel spittle-insect, Aphrophora parallella, Say. (ITomoptera. 
Cercopidse.) 
In June, a spot of white froth, resembling spittle, appearing 
upon the bark near the ends of the branches, hiding within it a 
small white wingless insect having six legs, which punctures 
and sucks the fluids of the bark, and grows to about a quarter 
[Ag. Trans.] 47 
