INSECT ENEMIES OF EASTERN FORESTS 597 
insect has two generations annually. The first brood appears early 
in May from galls of the preceding year’s growth, and the second 
brood in June from green galls. Females of the second brood oviposit 
in the galls from which they were produced. The early summer 
brood is made up of both sexes, whereas the overwintering brood is 
made up entirely of females. The species sometimes causes injuries 
by deforming young trees. Control is the same as for Callirhytis 
punctata. 
Disholcaspis eldoradensis Beut. forms slightly elongated bulletlike 
galls on twigs of Quercus lobata, 
known locally as river-bottom oak, or 
California white oak. The galls 
burst out of cracks in the bark along 
the internodes. The lower half of 
the gall is tan colored and rather 
smooth, whereas the upper side is 
darker and deeply fissured. During 
the early stages of growth this rugose 
surface secretes an abundance of 
honeydew, which is often a valuable 
food for bees. About the middle of 
August the first galls appear. They 
produce honeydew for several days 
and are followed by a succession of 
galls a little farther along the same 
twig. In California the yield con- 
tinues until the early rains late in 
October or early in November. The 
galls are said to be more plentiful fol- 
lowing a mild winter or a very dry 
summer. ‘Their chief economic value 
les in the fact that they appear so 
late in the season that the bees are en- 
couraged to raise a late brood, and 
honey produced from such nonfloral 
excretions is of good quality. The 
oalls usually appear locally, but cer- 
a = y Me ‘ea oe 1 Ficure 179.—The oak potato gall 
tain trees are heavily infested year (Neuroferus baiaiusy © Courtesy 
after year. Amer. Mus. Nat. Hist.) 
LEAF GALLS 
Amphibolips confluentus (Harr.), the large oak-apple gall (fig. 
180), is one of the most common and conspicuous oak galls. It is a 
nearly globular leaf or petiole swelling, from 1% to 2 inches in diameter 
and greenish or brownish in color, depending on its age. ‘The interior 
is filled with a spongy mass, in the center of which is a single larval cell. 
The galls appear on the leaves early in the spring. Some of them pro- 
duce both male and female adults in June, whereas others produce fe- 
males in October. It is a common gall on many of the eastern oaks 
(Quercus borealis, Q. coccinea, Q. velutina, and others), but it cannot 
be considered injurious. 
Galls of the species Vewroterus floccosus (Bass.), the oak flake gall 
(fig. 181), are commonly found on the under surface of the terminal 
