Kinsey: The Genns Neuroterus 
93 
walls thin and without any other cell lining, each cell about 1.7 by 
1.0 mm.; clusters up to about 15. mm. in diameter contain I'P to 60 
cells; succulent as the young leaf; on the young leaves of Quercus 
Douglasii (figs. 49, 50). 
RANGE. — California: Stanford University, Brentwood (Mc- 
Cracken) ; Diablo (F. A. Leach coll.) ; Redding, Oroville, Merced Falls, 
Three Rivers. Probably wherever Q. Douglasii occurs. 
TYPES. — 39 females, 11 males, and 40 clusters of galls. Holotype 
female, paratype females, males, and galls in The American Museum 
of Natural History; paratype adults and galls in the U.S. National 
Museum, Stanford University, the Philadelphia Academy, and the Kin- 
sey collection; paratype galls at the British Museum. Labelled Redding, 
California; April 2, 1920; Q. Douglasii; Kinsey collector. 
The gall of this species appears abundantly very early 
in the spring, with the unfolding of the leaves of the oaks. 
The insects mature within a very short time, and the galls 
are empty within a few weeks. Adults emerged in 1920 on 
March 22 at Three Rivers, on April 1 at Oroville, and April 
2 at Redding, the later localities being further north. Differ- 
ent trees at a single locality show great differences in the 
dates of development of these galls, indicating that the insect 
is considerably dependent upon the state of its host. Of 366 
insects I have bred, only 99, or 27 per cent, are males. This 
is still lower than the percentage for the related irregularis, 
but inasmuch as three separate collections agree in this respect 
it may be true that the males are disappearing from the 
species. An alternate, agamic generation undoubtedly does 
exist, but does not appear to have been discovered as yet. 
McCracken and Egbert record Quercus dumosa and the re- 
lated Q. durata as further hosts of decipiens. Undoubtedly 
a distinct variety of the insect is represented, distributed thru- 
out more southern California. It is peculiar that this gall 
has not been recorded from Q, lobata. 
Decipiens is the Pacific Coast equivalent of irregularis, 
just as many other American species are paired, eastward 
and westward, showing common origins but sufficient isolation 
to have evolved distinct groups of varieties. The differences 
between irregularis and decipiens are not many, but they are 
distinct and involve insects, galls, and distributions. 
