36 SCALE INSECTS OF SANTA CRUZ PENINSULA 



Pulvinaria vitis (Linnaeus). 



I have once taken this species from maples on the Stanford campus. 

 It is probably more or less distributed throughout this area, but is cer- 

 tainly not abundant. 



Genus SAISSETIA Deplanches. 3 

 Saissetia oleae (Bern.). 



Abundant upon a wide range of hosts. Among the wild plants that 

 it especially favors are mistletoe and Baccharis pilularis. It has also been 

 taken from Grindelia cuneifolia, Solatium sp. and Ceanothus sp. 



Saissetia nigra (Nietn.). 

 This has been taken on Euonymus sp. on the Stanford campus. 



Genus COCCUS Linn. 

 Coccus hesperidum Linn. 



A very common species on a wide range of wild and cultivated 

 hosts. 



Coccus citricola Campbell. 

 Said to occur at San Francisco. I have not seen specimens. 



Genus LECANIUM Burm. 

 Lecanium corni (Bouche). 



What appears to be entirely typical L. corni is abundant here on 

 mulberry, apricot, prune, and other cultivated hosts. What is supposed 

 to be this species has been taken from a long series of wild hosts, ^n- 

 cluding Alnus rhombifolia, Adenostoma fasciculatum, Arbutus menziesii, 

 Ceanothus sp., Acer macrophyllum and Heteromeles arbutifolia. From 

 the two last named hosts it has been described as new under the names 

 of L. crawii Ehrh. and L. adenostoma Kuwana. 



There is a very considerable diversity in appearance among speci- 

 mens from these various hosts, ranging from a large, pruinose form on 

 elm to a very small and shiny form on Arbutus, but there appear to be 

 no structural differences. Whether all these forms belong to a single 

 species can only be determined by extensive transference experiments. 



3 There is no evidence that S. hemisphaerica occurs out of doors in this 

 area, although I have seen some of the small and shiny forms of Lecanium corni 

 identified as this species. 



