40 MISCELLANEOUS STUDIES 



Pterocwnnia Buckton, in which the cornicles were cylindrical. He 

 states in his later paper : "... after having further studied the group 

 I am of the opinion that such a divsion is illogical, and if a division 

 is necessary each species should form a different genus. It, therefore, 

 seems more practical to confine all the species to a single genus. ' ' The 

 characters of this tribe and genus are as follows : 



Antennae with six segments and reaching near the base of the abdomen. 

 Wings normally with venation as in Aphis. Nectaries [cornicles] short, but 

 clavate. Cauda short and broadly rounded at the tip as in Lachni?ii. Entire 

 body, antennae, and legs covered with long hairs as in Lachnini. As has already 

 been pointed out by Oestlund, this group appears intermediate between the Clw.Uo- 

 phorini and the Lachnini. Their habits and actions being in different ways similar 

 to both. 



17. Genus Pterocomma Buckton 



Buckton, Monog. Brit. Aphides, vol. 2, p. 143, 1879. Type P. pilosa 

 Buckton. 



KEY TO CALIFORNIA SPECIES 



1. Cornicles abruptly constricted at distal end, and without a distinct flange 



(fig. 81), the diameter of the opening being less than the diameter of the 

 smallest part of the cornicle. Wing veins broad and shaded. 



flocculosa (Weed) 



Cornicles not so abruptly constricted and with a distinct flange. Wing 



veins normal 2 



2. Cornicles about twice as long as their greatest diameter ....smithiae (Monell) 



Cornicles considerably longer than greatest diameter, and longer than hind 



tarsus populifoliae (Fitch) 



40. Pterocomma flocculosa (Weed) 



Figure 81 



Weed, Insect Life, vol. 3, p. 291, 1891. Melanoxanlhus (orig. desc.). 

 Wilson, Ann. Ent. Soc. Am., vol. 8, p. 350, 1915 (desc.). 



Records. Salix sp., Berkeley, March, 1915; 1916 (Essig). 



In his paper on Pterocomma Wilson states that this species does 

 not occur on the Pacific Coast. However, in March, 1915, the author 

 found it rather abundantly on willow on the campus of the University 

 of California in Berkeley. During the 1916 season Essig observed it 

 to be quite common in Berkeley. The species is easily recognized in 

 life by the white cottony flocculence covering the colonies on the bark. 



