98 
Indiana University Studies 
Galls generally elongate, oval, as thick as wide, up to 5. mm. wide by 
15. mm. long, several galls often fusing; green, very succulent, shrivel- 
ling considerably upon drying; solid, the larval cell with a distinct but 
inseparable lining, lying mostly below the surface, only rarely evident 
on the surface. Smooth, naked, and larger when on Quercus alba; very 
pubescent and smaller when on Quercus stellata (fig. 52). 
RANGE. — Ontario to Texas. Probably thruout eastern North 
America. 
The galls of this species appear on the very young, un- 
folding leaves, and very quickly mature, the insects emerg- 
ing before the leaves are fully expanded. This, of course, 
is earlier further south, April and May, to early June in New 
England. The galls become shrivelled and decayed, and only 
a few remnants will be found later in the summer. Of 430 
insects which I have bred for all varieties, 167, or 39 per cent, 
are males. This is higher than the percentage for the related 
decipiens, but may show a tendency toward the reduction of 
the male. 
This is clearly the eastern equivalent of Neuroterus 
decipiens, but the two are distinct species. The present 
species is closely related to N euroterus minutus, but irreg- 
ularis, altho one of its varieties is the type of the subgenus, 
is certainly an extreme in Dolichostrophus. Irregularis vari- 
eties are very poorly defined, and rest in all but one instance 
on color and size characters, the males being most distinctive. 
Apparently the eastern third of the United States does not 
possess the sharply defined faunal areas of the Pacific Coast, 
and the more uniform geography of the east would lead one 
to expect this. Further, the eastern oaks are in many in- 
stances more closely related than those of the west, and host 
isolation, in irregularis at any rate, does not appear to have 
developed distinct insects. These conditions, combined with 
considerable individual variation, so obscure the group vari- 
ation that I would hesitate to determine single specimens of 
the females and sometimes of the males of varieties of this 
species. 
About 40 varieties may be found on the white oaks proper 
of the eastern half of the United States. The following ref- 
erences are to probably undescribed varieties of irregularis. 
ISJ euroterus majalis Ashmead, 1887, Trans. Amer. Ent. Soc., XIV, p. 139 
(Florida, on Q. Prinus) . Beutenmuller, 1910, Bull. Amer. Mus. 
Nat. Hist, XXVIII, p. 134 (Florida record only). Cosens, 1912, 
Trans. Can. Inst., IX, p. 354, fig. 67 (Ontario, on Q. alba). 
