318 AMERICAN POMOLOGY. 



sects soon cripple the growth of the shoot. The species 

 is not known to be different from that of Europe. This 

 insect is briefly mentioned by T. Glover, in Patent Office 

 Rept. for 1854, p. 79. Dr. Fitch describes as a grape leaf- 

 louse, the Pemphigus vitifolia, which inhabits the gall- 

 like excrescences upon the foliage of some varieties, par- 

 ticularly those with thin leaves. 



Aphis riMs, (Linn.), is the Aphis of the currant. It 

 causes the leaves to present a blistered appearance above ; 

 the lice are found on the under side ; the wingless are pale 

 yellow, the others have glossy wings, mostly black, with 

 abdomen light green.* 



Aphis lanigera, now called J&riosoma, or the Woolly 

 Aphis, was first described in 1801 as infesting the apple 

 trees in Germany. It has been noticed in England in 

 1787, and has since acquired the name of American Blight, 

 from the erroneous supposition that it had been imported 

 from this country ; but it was known to French gardeners 

 for a long time previous. 



The eggs of this insect are microscopic, and are envel- 

 oped in a cottony substance. They are deposited in 

 chinks of bark, and crotches of limbs, at or near the sur- 

 face of the ground. When first hatched, the insects are 

 covered with short down; as they grow, the down in- 

 creases in length. When fully grown, they are one-tenth 

 of an inch long; the head, antennae, sucker, and skins, 

 are blackish, the abdomen of a honey-yellow color. Their 

 punctures produce warty excrescences, the limbs become 

 sickly, the leaves turn yellow and drop off, and the whole 

 tree perishes as the insects spread over it. The remedies 



* Lib. cit. p. 435. 



