February, '14] DAVIDSON: PLANT-LOUSE NOTES 127 



inspection certificate could be issued. Most of these had or were near 

 infestations of San Jose scale. To date 111 inspection certificates have 

 been issued, 57 dealers' certificates, 96 permits to outside nurserymen 

 and 294 agents' permits. This has kept the writer, with one assistant 

 and one deputy, during the summer season, busy, considering the fact 

 that we have also the college and station work to administer. We 

 have also been busy with the shipments of foreign stock, and have 

 begun the first of our winter demonstrations for the control of San 

 Jose scale. 



We feel that we have already made a slight beginning and with the 

 continued earnest cooperation of fruit growers, nurserymen and col- 

 leagues we hope to be able to protect all home interests affected by the 

 law, and to be of some assistance in the protecting of similar interests 

 in other states. 



PLANT-LOUSE NOTES FROM CALIFORNIA 



By W. M. Davidson, U. S. Bureau of Entomology, Walnut Creek, CalA 



Pemphigus californicus Davidson. Close observations on the habits 

 of this species indicate that it migrates towards the end of April from 

 the buttercup to the ash (Fraxinus oregona Nutt.). The third genera- 

 tion on the buttercup all become winged lice and forsake the plant 

 in a body. They and their immediate progeny cause the leaves of 

 the ash to curl in a manner similar to that caused by Peinphigus 

 fraxini-dipetalce Essig. In May, the shrivelled migrants may be 

 found in the curled leaves together with the apterous lice of the second 

 and third generations on the ash. These apterous lice have undeveloped 

 eyes, the first generation of them being large bloated individuals. 

 The third, or second apterous, generation on the ash is composed of 

 both winged and wingless individuals. 



Lachnus thujafalinus Del Guercio. Infests branches and twigs 

 of cultivated Thujas. In California winged lice appear in April. 

 Collected at Palo Alto and Walnut Creek, California. 



Lachnus ponderosa Williams. Observed in abundance in August, 

 1912, at Glenbrook, Nev., and Tallac, Cal. (elevation 6000 ft.) on 

 twigs and branches of Pinus ponderosa var. jeffreyi Vasey. 



Phyllaphis f querci Fitch. Mr. J. J. Davis has kindly identified this 

 louse described and figured by him in the Entomological News, Vol. 

 xxii, June, 1911. I have taken it in the fall on the under side of leaves 

 of Quercus agrifolia Nee, the sexed forms appearing in early November. 

 Towards the end of April, the stem mothers appear on the upper side 



» Published with the permission of the Chief of the Bureau of Entomology. 



