106 
Indiana University Studies 
This gall develops very early in the spring on the young 
aments, soon emerging in May or early June. My descriptions 
are made from a very large series of types. 
Neuroterus (Dolichostrophus) quercicola Dalla Torre 
Figures 51, 55, 57, 60, 63 
FEMALE. — Head black, shading to piceous yellow on the mouth- 
parts; antennae brown, yellow basally, with 13 segments, the third seg- 
ment half again as long as the fourth; thorax entirely black, hardly 
half again as long as wide and high, almost naked of hairs, the mesono- 
tum and mesopleurae mostly smooth, only very finely roughened ; abdomen 
black, much higher than long, decidedly produced ventrally in bisexual 
forms, not produced in agamic forms, triangulate; legs yellow, dark 
brown or brownish black on the coxae, femora, and hind tibiae except at 
the joints; areolet of moderate size or smaller; the terminal portion 
of the subcosta not as long as in decipiens; the first abscissa smoothly 
angulate, bent near the subcosta; length 1. 2-2.0 mm. 
MALE. — Eyes moderately enlarged, the thorax and abdomen piceous 
brown, the pleurae piceous brown to yellow, the third segment of the 
antenna more than half again as long as the fourth, moderately curved, 
the areolet a little larger than in the female. 
GALL. — Larval cells, with distinct but inseparable linings, scat- 
tered or clustered in various parts of the plant. Acorn galls and some 
twig galls are single larval cells in the wood of the cup or the stem, 
without much swelling. Leaf, stem, and flower galls usually produce 
irregular, polythalamous swellings closely packed with oval larval cells; 
of much the same color and surface as the part of the plant affected, 
distorting the tissue irregularly but usually into a rather elongate, cyl- 
indrical gall, succulent or papery or woody, permanent or evanescent, 
as is the nature of the affected plant tissue. Internally irregularly 
packed with cells, these very dense mostly toward the periphery. On 
flower stems, distorting the clusters of aments and sometimes involving 
the young stems, petioles, and leaf blades; or on leaf veins and involv- 
ing the blade; or affecting woody twigs; on western American white 
oaks (figs. 51, 55, 57, 60, 63). 
RANGE. — San Diego, California, to Puget Sound, Washington, and 
Manitou, Colorado; probably thruout the western half of North America. 
This species is clearly the western equivalent of Neuroter- 
us minutus of eastern North America. Beyond its generally 
darker color, quercicola diifers from minutus in the ventrally 
produced abdomen and the more angulate hrst abscissa. 
These would still leave it a question as to the specific distinct- 
ness of the two, but their ranges are clearly defined. Both 
quercicola and minutus exhibit remarkable polymorphism of 
gall structure. 
