152 MISCELLANEOUS STUDIES 



179. Chermes pinicorticis Fitch 



Fitch, Trans. N. Y. State Agr. Soc., vol. 14, p. 971, 1855. Coccus (orig. 



desc.). 



Storment, 20th Ann. Eep. Illinois St. Ent., appendix, 1898 (desc.). 

 Davidson, Jour. Econ. Ent., vol. 2, p. 299, 1909 (list). 

 Davidson, Jour. Eeon. Ent., vol. 3, p. 372, 1910 (list). 



Record. Pinus pinaster maritima; Stanford University (Davidson). 



This species, which is unknown to the author, was reported as 

 present at Stanford University on Pinus pinaster maritima, where 

 it was so abundant as to sometimes kill the young trees. For a com- 

 plete description see Storment 's paper listed above. 



Group Phylloxerina Borner 



There are two genera in this tribe, as considered by Borner and 

 Mordwilko, although the American authors have generally taken cog- 

 nizance of but one, namely, Phylloxera Boyer. Below is a key from 

 Mordwilko to these genera. 



1. Neither wingless females nor any other forms secreting any waxy material. 



Phylloxera Boyer 

 Wingless females secreting a waxy powder Phylloxerina Borner 



47. Genus Phylloxera Boyer 



Boyer de Fonscolmbe, Ann. Ent. Soc. France, vol. 3, p. 222, 1834. Type 

 P. quercus Boyer. 



180. Phylloxera vitifoliae Fitch 



Fitch, Eept. Ins. N. Y., vol. 1, p. 58, 1855 (orig. desc.). 



Planchon, C.-E. Aead. Sci. Paris, vol. 67, pp. 588-594, 1868. P. vastatrix 



(desc.). 



Clarke, Can. Ent., vol. 35, p. 248, 1903. P. vastatrix Plan (list). 

 Davidson, Jour. Econ. Ent., vol. 2, p. 299, 1909. P. vastatrix Plan. (list). 



Davidson, Jour. Econ. Ent., vol. 3, p. 372, 1910. P. vastatrix Plan. (list). 

 Records. Grape; Central and Northern California. 



This is the only species of this genus reported in California. It 

 is one of the most destructive species of plant lice in this section of 

 the country, having in its time practically wiped out the grape indus- 

 try of Santa Clara Valley, and of many other parts of the state. It 

 seems that in California this species infests the roots only of the grape, 

 the forms that produce the leaf galls in the eastern parts of the 

 country not being found here. 



