BjI. 903. U. S. Deot. of Agriculture 
Plate IV. 
y V 
The Grape Phylloxera in California. 
Phylloxei i ie: Fig. 1.— Phylloxera nodosities shown on Ziniandel grapevine: 
a, Nodosities on Terminal rootlet's: h. nodosity showing Phylloxera feeding: c.adult louse; 
d, molted skin of same. Fig. 2. — Phylloxera tuberosities on smaller root: a, Infested 
portion of root: b. normal portion of foot. Fig. 3.— Section o: grapevine root showing 
adult louse witheggstn situ. Fig. 4. — Sections of root infested: a. Newly formed tuber- 
ositv: b, advanced^stage of tuberosity: c. side view of older form of Tuberosity: d. tuber- 
osity- causing the cracked condition of bark; e. voung colony of insects as found on roots. 
