HEMIPTERA. 221 



observed; but it is by no means clear that they are of the 

 same species as those on the apple-tree. The first account 

 that we have of the occurrence of bark-lice on apple-trees, in 

 this country, is a communication by Mr. Enoch Perley, of 

 Bridgetown, Maine, written in 1794, and published among 

 the early papers of the Massachusetts Agricultural Society.* 

 These insects have now become extremely common, and in- 

 fest our nurseries and young trees to a very great extent. In 

 the spring the eggs are readily to be seen on raising the 

 little muscle-shaped scales beneath which they are concealed. 

 These eggs are of a white color, and in shape nearly like those 

 of snakes. Every shell contains from thirty to forty of them, 

 imbedded in a small quantity of whitish friable down. They 

 begin to hatch about the 25th of May, and finish about the 

 10th of June, according to Mr. Perley. The young, on their 

 first appearance, are nearly white, very minute, and nearly 

 oval in form. In about ten days they become stationary, and 

 early in June throw out a quantity of bluish white down, soon 

 after w^hich their transformations are completed, and the 

 females become fertile, and deposit their eggs. These, it 

 seems, are hatched in the course of the summer, and the young 

 come to their growth and provide for a new brood before the 

 ensuing winter. 



Among the natural means which are provided to check the 

 increase of these bark-lice, are birds, many of which, especially 

 those of the genera Partis and Reg^ilus, containing the chick- 

 adee and our wrens, devour great quantities of these lice. I 

 have also found that these insects are preyed upon by internal 

 parasites, minute ichneumon flies, and the holes (which are as 

 small as if made with a fine needle), through which these little 

 insects come forth, may be seen on the backs of a great many 

 of the lice which have been destroyed by their intestine foes. 

 The best application for the destruction of the lice is a wash 

 made of two parts of soft soap and eight of water, with which 

 is to be mixed lime enough to bring it to the consistence of 

 thick whitewash. This is to be put upon the trunks and limbs 



« See papers for 1796, p. 32. 



