254 HEMIPTEEA. 



especially those of the genera Parus and Regulus, contain- 

 ing the chickadee 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 of the trees with a brush, and as high as 

 practicable, so as to cover the whole surface, and fill all the 

 cracks in the bark. The proper time for washing over the 

 trees is in the early part of June, when the insects are young 

 and tender. These insects may also be killed by using in 

 the same way a solution of two pounds of potash in seven 

 quarts of water, or a pickle consisting of a quart of com- 

 mon salt in two gallons of water. 



There has been found on the apple and pear tree another 

 kind of bark-louse, which differs from the foregoing in many 

 important particulars, and approaches nearest to a species 

 inhabiting the aspen in Sweden, of which a description has 

 been given by Dalman in the " Transactions of the Royal 

 Academy of Sciences of Stockholm,"* for the year 1825, 

 under the name of Coccus cryptogamus. This species is 

 of the kind in which the body of the female is not large 

 enough to cover her eggs, for the protection whereof another 

 provision is made, consisting, in this species, of a kind of 

 membranous shell, of the color and consistence almost of 

 paper. In the autumn and throughout the winter, these 

 insects are seen in a dormant state, and of two different 

 forms and sizes on the bark of the trees. 



The larger ones measure less than a tenth of an inch 

 in length, and have the form of a common oyster-shell, 

 * Kongl, Vetenskaps Academ. Nya Handlingar. 



