﻿AMERICAN CYNIPID GALL WARPS — WELD 337 



the ground for the winter. When examined on ;Maroh 15, 1950, many 

 adults had emerged and died while other galls still contained larvae. 

 These galls occur also on Quercus agnfolki and Q. keUoggii. 



DRYOCOSMUS MINUSCULUS, new species 



Female.— Blaok] mandibles, antennae and legs mostly brownish. 

 Head coriaceous; from above transverse, cheeks slightly broadened 

 behind eyes, occiput concave; from in front broader than high, malar 

 space .4 eye, without groove, antennae 14-segmented, last 8 with rhi- 

 naria. Sides of pronotum striate in part. Mesoscutum bare, polished, 

 parapsidal grooves percurrent. Scutellum with two smooth circular 

 pits at base; disk coriaceous behind septum, rugose behind. Meso- 

 pleuron bare, smooth. Wing pubescent, ciliate, veins pale, areolet 

 small, radial cell four times as long as broad. Claws simple. Carinae 

 on propodeum slightly bent, enclosed area broader than high. Abdo- 

 men plump, in side view gibbous below petiole, tergites along dorsal 

 curvature as 43 : 10 : 10 : 10 : 13 : 1, III-VI sparsely punctate, VII cori- 

 aceous, tip of ovipositor projecting beyond sheath curved. Ventral 

 spine eight times as long as broad, slightly longer than hind metatar- 

 sus. Using width of the head as a base the length of mesonotum ratio 

 is 1.3; antenna 2.4; wing 5.0. Length 1.75-2.05 mm. Average of five 

 specimens 1.91 mm. 



Differs from Dryocosmvs hicomis (McCracken and Egbert), which 

 is straw yellow and has the ovipositor straight at the tip. D. hicomis 

 forms galls on the same hosts as does D. minvsctiJus. 



Tyyes. — U.S.N.M. No. 60125 : Type and one paratype. Paratypes 

 also in C.A.S., and A.M.N.H. 



Host. — Quercus ag ri folia. 



Gall (pi. 17, fig. 13) . — Small brown galls up to 2.7 mm. in diameter, 

 shaped like a depressed sphere with a minute pit in the center above. 

 Produced on upper side of leaves of Quercus agrifolia^ Q. wislizeni, 

 and rarely on Q. kelloggii in the fall and dropping when mature. Said 

 to be so numerous sometimes as to defoliate the tree. Some years these 

 galls are not common. 



Habitat. — The types were reared from galls collected October 22, 

 1939, on Quercus ognfolia on Mount Diablo, Calif. Adults emerged 

 April 17, 1941. Galls have been noted on this host at some 40 local- 

 ities between Alpine and Ukiah and Red Bluff, Calif. They are also 

 common on Quercus imsUzeni and have been seen on Quercus kelloggii 

 a few times. The guest fly, Syiiergus agrifoliae Ashmead, often reared 

 from it, varies much in color pattern and has been redescribed as 

 Synergus maculatus Fullaway (1911) new synonymy, and as Synergus 

 ohscums McCracken and Egbert (1922), new synonymy. 



