THE PEAR-TREE PSYLLA. 233 



isli. 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 vary in color at different 

 ages, 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 

 fi'om abroad, and that they will prove to be the same species 

 as the European Psylla Pyri. 



The following particulars, abridged from Kpllar'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 tlie 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. 



Wlien considerable numbers attack a pear-tree, the latter 

 30 



