596 MISC. PUBLICATION 657, U. 8S. DEPT. OF AGRICULTURE 
the horned oak gall (fig. 177), occur on twigs and branches of pin 
oak (QYuercus palustris), scrub oak (@. ilictfolia) blackjack oak (@. 
marylandica), black oak ( Q. v ate): and water oak (Q. nigra 
and varieties) throughout the eastern part of the United States and 
westward into Texas. They differ in appearance from gouty oak 
galls in having hollow conelike protuberances or “horns,” through 
which the adults emerge early in the spring. The life history of the 
insect and the damage caused by it, are very similar to what has just 
been described for the gouty oak 
gall, and control is the same for both 
species. 
Andricus clavigerus Ashm. is an- 
other horned oak gall that is very 
abundant and is injurious to the 
southern willow oak (Quercus phel- 
los). It is larger ae Callirhytis 
corntg era and frequently more 
abundant. Life history, economic 
damage, and control are as described 
for the gouty oak gall. A. aqua- 
tecae. ( Ashm. ) also forms terminal 
or subterminal swellings of branches 
and twigs. It is abundant on black 
oak (Y. velutina) and water oak (Q. 
ni ary in the Southeastern States. 
It is usually localized on certain 
trees, and pruning is the most prac- 
tical method of control. 
The galls of Andricus gemmarius 
(Ashm. ), the ribbed bud gall (fig. 
178), are somewhat conical, strongly 
ribbed and are about 34¢ inch long. 
They are found in crowded masses 
along longitudinal cracks in the 
bark. The species is generally dis- 
tributed over the eastern half of the 
United States and has been recorded 
on red oak (Quercus borealis), black 
oak (Q. velutina), and blue jack oak 
(QY. cinerea). A sweetish secretion 
with the ribbed bud gall (Andricus exudes from the galls early in the 
gemmarius), and one gallenlarged = SUImMer and attracts hosts of bees 
four diameters. (After Felt.) and flies. A serious infestation 
kills twigs and may even kill young 
trees. In his discussion of the American insect galls, Felt (153) in- 
cluded this species as Callirhytis gemmaria, and MeDaniel (283) 
included this species in a bulletin on the Michigan galls. For see 
prune infested twigs, as for Callirhytis punc tata. 
Neuroterus batatus (Fitch), the oak potato gall (fig. 179), forms 
swollen, uneven, stem galls, resembling a potato, about 34 inch thick 
and two or three times as long, on white oak (Quercus alba) and 
related forms. It occurs throughout the northeastern quarter of the 
United States. Internally this peculiar deformity of the twigs has 
a dense corky texture, and is composed of numerous larval cells. The 
FicurRE 178.—Twig badly infested 
