THE PEAR-TREE PSYLLA. 
233 
ish. Their four ample wings were colorless and transparent, 
and were marked with a few dark veins. The body of the 
female is pointed at the end, and inclines to a reddish 
hue. ■ 
The pear-tree, in Europe, is subject to the attacks of 
a similar insect, called Psylla Pyri, the pear-tree Psylla. 
The European species is said to vaiy in color at different 
aces, and in different seasons of the year, being of a dull 
crimson color, shaded with black in the spring, when it 
comes forth to lay its eggs. Not having seen any of our 
pear-tree Psyllce in their spring dress, I cannot say whether 
they agree with those of Europe in being of the same crim- 
son color at this season of the year. As, however, they do 
correspond very nearly in other respects to the descriptions 
given of the European species, and have precisely the same 
destructive habits, and as they were first detected upon 
imported pear-trees, I apprehend that they were introduced 
from abroad, and that they will prove to be the same species 
as the European Psylla Pyri. 
The following particulars, abridged from Kollar’s “ Trea- 
tise,” if confirmed by future observations, will serve to 
complete the history of the American insect. The European 
pear-tree Psylla comes forth from its winter retreat, pro- 
vided with wings, as soon as the buds of fruit-trees begin to 
expand. After pairing, the female lays her eggs in great 
numbers near each other on the young leaves and blossoms, 
or on the newly-formed fruit and shoots. The eggs are 
oblong, yellowish, and look somewhat like grains of pollen. 
The young insects hatched therefrom resemble wingless plant- 
lice, and are of a dark yellow color. They change their 
skins and color repeatedly, and acquire wing-scales, or rudi- 
mentary wings. They then fix themselves to the bark in 
rows, and remain sucking the sap till their last change ap- 
proaches, at which time they disperse among the leaves, 
cast off their skins, and appear in the winged form. 
When considerable numbers attack a pear-tree, the latter 
30 
