LIBRARY

338 COLLEGE ENTOMOLOGY
The two species Pterocomma populea (Kalt.), infesting the stems of poplars,
and P. salicis (Linn.), on willows, are common to Europe and North America.
They are large brown aphids with short bright-orange cornicles. Their honeydew
is often an abundant source of honey for the common honeybee.
The genus Aphis Linn. is a very large one and has been divided into a
number of genera during the past few years. Some of these names are Brachy.
FIG. 115. The latania aphid, Cerataphis latanire (Boisduval),
a tropical American species common on orchids, Bourbon palm,
sweet flag, and other plants grown in greenhotlses. Apterotls
aleyrodiform females, (From Insects oj Western North America.)
caudus v.d. Goot, Appelia Borner, Ye2abura Matsumura, Doralis Leach, and
Anuraphis Del Guercio. They are not employed here because their validity
is still uncertain. Some of the very common species occurring in Europe,
North America, and other parts of the world are: Aphis sambuci (Linn.)
(= sambucifolire Fitch), a dark species on elderberry; A. medicaginis Koch,
a shiny black aphid on legumes and other plants; A. grossulariCl3 Kalt., curling