Kinsey: The Genus Neuroterus 
81 
MALE. — Largely agrees in color with the female, the thorax piceous 
laterally, the legs and antennae uniformly yellow; abdomen with the 
petiole piceous or lighter in color; eyes only slightly enlarged; the third 
segment of the antenna not longer than in the female, only slightly 
curved; areolet smaller than in the female. 
GALL. — A woody, elongate stem swelling, wholly inseparable. Poly- 
thalamous, with a great many larval cells. Of irregular surface and 
shape, twisted, but in large part cylindrical, tapering gradually to the 
stem at either end; up to 20. mm. in length and 8. mm. wide (bisexual 
forms), or 60. mm. long by 20. mm. wide (agamic forms); but some- 
times several galls more or less fused, the surface covered with normal 
bark, drying brown in bisexual forms, with a whitish or purplish bloom 
in the agamic forms. Internally hard and woody, the tissue not con- 
siderably modified except by the larval cells, these cells densely packed, 
largely toward the surface, each with a distinct but wholly inseparable 
lining. The agamic form on young stems, involving petioles and leaf 
midveins, the bisexual form on older stems involving the bases of the 
petioles; on white oaks (figs. 56, 61). 
RANGE. — Ontario to Michigan and Texas; probably thruout east- 
ern North America. Similar galls from the Rocky Mountains may 
belong to a different species. 
This species has been of more than usual interest because 
we have long known the life histories of two of the varieties, 
batatus and noxiosus. I have already published an account 
of these (1920, Bull. Amer. Mus. Nat. Hist., XLII, pp. 333- 
338). Summarizing, connections of the two generations were 
made in each case by Homer F. Bassett on observations dating 
from 1864 to 1873 ; he saw the alternating abundance of the 
two kinds of galls, and the great similarity amounting almost 
to identity of the galls and insects of the two generations, 
no exact experimental proofs being obtained; but all succes- 
sive workers who have handled the species can confirm Bas- 
sett’s data. Variety batatus furnished the first known in- 
stance {Andricus operator was the first case experimentally 
proved) of heterogeny among the Cynipidse, while noxiosus 
was the fourth and last case Bassett studied. The agamic 
forms begin development in mid-summer, forming woody stem 
galls in which the insects spend the winter, emerging in the 
spring after the oaks are well growing. The bisexual gen- 
eration forms less woody galls on younger parts of the plant, 
the insects developing quickly and emerging in June or early 
July, this generation producing females and males in about 
equal numbers. All this applies equally to varieties batatus, 
noxiosus, and prini in the northeastern parts of the U.S. 
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