Ins efts and Diseases. 149 



from a dozen to a hundred of which lie in the cavity under each 

 scale. These eggs hatch the latter part of May, and the young lice 

 diffuse themselves over the bark, appearing as minute white atoms, 

 almost invisible to the eye. They puncture the bark, and suck the 

 sap from it. The females soon fix themselves and become stationary. 

 They die and become overspread with a substance resembling fine 

 blue mould, which, wearing off, the little oyster-shaped scale again 

 appears in July. They sometimes become so multiplied that the 

 bark of the trunk and limbs is everywhere covered and crowded 

 with them, and if the tree is weakened by borers, fire blight, or other 

 disease, these bark-lice thus multiplying, kill it. In years past, over 

 all the country adjacent to Lake Michigan, every apple-tree has been 

 destroyed by this insect." 



The late A. G. Hanford was successful with a mixture of equal 

 parts of tar and linseed oil, applied warm, not hoi, early in spring, to 

 the bark. This mixture does not continue soft and spread over the 

 surface and close the pores so as to kill the tree, as grease would do ; 

 but it forms simply a varnish, which soon becomes hard, and when 

 the tree appears in leaf and begins to grow, this varnish cracks and 

 peels off, carrying the bark-lice with it, and leaving the bark fresh 

 and smooth. Dr. Fitch, in his Treatise on Insects, mentions 

 another remedy which he considers very efficacious, prepared as fol- 

 lows : Leaf tobacco is boiled in a strong lye until reduced to an 

 impalpable pulp, and this is then mixed with soft soap (which has 

 been made cold, and not boiled), the whole mixture becoming of the 

 consistence of thin paint ; this, when applied, does not easily wash 

 from the tree, as lye, tobacco water, etc., would alone. One applica- 

 tion with the brush to every part, will protect trees two years. A 

 young orchard of one hundred and fifty trees, required two men a 

 fortnight to go over every part, branch and twig, through the orchard. 

 The trees grew thriftily, and were perfectly free from lice, while others 

 in every direction were dying from their attacks. 



Quassia, soda wash, etc., have been strongly recommended, but 

 are much less efficient. Scraping and scrubbing, in summer, with a 

 stiff brush, in soap suds are useful. Thriftiness from good culture 

 is the best preventive ; and trees badly affected should be cut up 

 and burned. 



The Canker Worm (Anisopteryx vernata}. This caterpillar 

 appears to have been, as yet, chiefly confined in its destructive rava- 

 ges to portions of New England. The following figures represent 

 the perfect insect, the male with wings, the female nearly destitute 

 (Fig. 181). The canker worm attacks both fruit and leaves ; when 



