100 



Indiana University Studies 



the cup, only rarely producing a slight swelling on the outside of the 

 cup. On Quercus lobata. 



RANGE. — California: Paso Robles, Gilroy (Redwood School). 



TYPES. — oO females and many infested acorns; holotype female, 

 paratype females, and galls in The American Museum of Natural His- 

 tory; paratype females and galls at Stanford University, the U.S. Na- 

 tional Museum, the Museum of Comparative Zoology, the Philadelphia 

 Academy, and with the author. Labelled Paso Robles, California, March 

 7, 1920, Kinsey collector. 



Adults were emerging at Paso Robles on March 7, after 

 most of the cupules had fallen to the gromid. This is clearly 

 an agamic generation, and very probably has an alternate, 

 bisexual generation, probably not occurring on acorn cups. 

 A similar gall occurs on Q. gar ry ana on the north Pacific 

 Coast; the insects will probably prove to belong to a distinct 

 variety. 



Neuroterus evanescens, new species 



Almost wholly black, straw colored on the antennae and parts of the 

 legs; areolet moderately large; length 1.0 mm. or less. 



FEMALE. — HEAD: As broad or broader than the thorax, pro- 

 truding slightly behind the eyes ; wholly black except the straw^ yellowish 

 mouth-parts ; apparently smooth, but microscopically coriaceous, most 

 so toward the mouth. Antennae light straw^ yellow; very finely pubes- 

 cent; with 13 segments, the third the longest but not much longer than 

 the fourth, the last about as long as the preceding. THORAX: En- 

 tirely black or piceous black; mesonotum almost entirely smooth, shining, 

 without lines or grooves; scutellum almost smooth, shining, with a very 

 few hairs, the groove at the base only slightly arcuate; pronotum piceous 

 black, very finely roughened; mesopleurae piceous black, very finely 

 rugoso-aciculate. ABDOMEN: Piceous black or black; smooth, naked; 

 small, about triangular, shrivelling, extending ventrally as far as or 

 further than dorsally. LEGS: Dark brown, light straw brown at the 

 joints and on the tarsi, the tips of the tarsi darker; very finely hairy; 

 tarsal claws simple. WINGS: Very clear, edges ciliate; veins straw 

 brown, distinct; areolet of moderate size; cubitus reaches the basalis; 

 radial cell entirely open, not as long and narrow as usually in the 

 genus; second abscissa of the radius practically straight; first abscissa 

 distinctly angulate but without a projecting tip. LENGTH: 0.7-1.0 mm. 



MALE. — Similar to the female, but with 14 segments to the an- 

 tennae; legs almost w^holly straw brown; abdomen much smaller, with a 

 more distinct but not long pedicel. 



GALL. — Very slight swelling of the stem of the ament, causing an 

 abortion of the whole ament into a short, ovoid mass about 5. mm. long, 

 covered closely with clustered but otherwise normal anthers. The lai-val 

 cells are tiny cavities in the swollen stem, without distinct linings, cov- 

 ered on the outside by only very thin tissue. On aments of Quercus 

 breviloba. 



