480 THE PEAR-TREE SLUG. 



long, colored lemon above, glistening like burnished 

 gold on the top of the head and thorax ; the body 

 beneath is copper colored, and thickly covered with 

 whitish wool " [Harris). 



(2) The Red Mite — Acarus geniculatus : Linn. 

 This little insect is gregarious, congregating in the 

 spring at the base of the twigs, and is often found 

 in great numbers. It attacks the foliage of many 

 fruit trees, particularly the pear.* It causes a pecu- 

 liar and sickly hue on the leaf. It can be distin- 

 guished at a distance by the reddish tinge of its 

 body. If unmolested, it destroys the tissue of the 

 leaf, and thereby induces one of those diseases re- 

 sulting from weakness. The insect becomes darker 

 colored with age, attains about the size of a grain 

 of very fine gunpowder, and during the winter lives 

 under old bark or lichens. It may be destroyed by 

 a profuse syringing of whale-oil soap-water, like 

 that used for canker worms. 



(3) The Pear-tree Slug — Selandria Aethiops. This 

 is the slimy larva of the saw-fly, and feeds upon the 

 leaves of the pear. It is found upon the upper sur- 

 face, solitary, or in groups of two or three. It is 

 about five-eighths of an inch in length, is green in 

 color, becoming darker with age. It eats nothing 

 but the soft parts of the leaf, and commits its rava- 

 ges in June and July. If unmolested, it strips the 

 tree of its foliage. It is particularly injurious in 

 seasons of drought. In that of 1864, two generations 



