PLANT LICE. 5 
Phylloxera vastatrix Planch. (The Grape-vine Phylloxera). 
A most excellent account of this insect was given by Mr. 
Marlatt in one of the Farmer’s Bulletins issued by the Depart- 
ment of Agriculture, and it is here repeated as well as the illus- 
trations (Fig. 143): 
“This insect has always existed on our wild vines, yet it 
was not until it had been introduced abroad and began to ravage 
the vine-yards of the Old World that particular attention was 
drawn to it as a vine pest, or that anything definite was known 
Fic. 143a—Pylloxera vastatrix Plach.:ja, leaf with galls; b, section of galls show- 
ing mother louse at center with young clustered about; c, egg; d, larva; e, 
adult female; f same from side—a, natural size, rest much enlarged. After 
Marlatt, Div. of Entomology, Dep. of Agriculture. 
of its habits. It appears in two destructive forms on the vine, 
the one forming little irregular spherical galls projecting from 
the underside of the leaves, and the other subsisting on the roots 
and causing analogous enlargements or swellings. The leaf form 
is the noticeable one and is very common on our wild and cul- 
tivated vines. The root form is rarely seen, but is the cause 
of the real injury done by this insect to the vine, and while 
hidden and usually unrecognized, its work is so disastrous to 
varieties especially liable to attack that death in a few years is 
almost sure to result. It first produces enlargements or little galls 
on the rootlets. As it extends to the larger roots these become 
