Page:New Pacific Coast Cynipidæ (Hymenoptera).pdf/13

From Wikisource
Jump to navigation Jump to search
This page has been validated.
1922]
Kinsey, New Pacific Coast Cynipidæ
291

tions to Andricus pomiformis (Bassett). Adults emerged from galls at Placerville, California on March 30; but it is likely that there is an earlier emergence date for more southern material. The gall is prominent and very abundant wherever I have seen Quercus chrysolepis.

Bassettia ligni, new species
Plate XXIV, Figure 1

Female.—Almost wholly black; the thorax transversely rugulose, lateral lines distinct; edges of wings not ciliate; length, 1.7 mm. Head: Slightly wider than thorax, bulging behind eyes; black, rufous brown at mouth; coriaceous to shagreened. Antennæ almost black, rufous brown basally. Thorax: Elongate; entirely black; prominently but shallowly puncto-rugose, or transversely rugulose, naked of hairs; parapsidal grooves fine but distinct to the pronotum where they are gradually curved apart, gradually curving together at the scutellum; median groove very fine and short, a fine, median, shallowly rugose depression extending anteriorly; anterior parallel grooves fine, extending posteriorly not much more than a third the length of the mesothorax; lateral lines smoother areas or shallow grooves, distinct, short, not reaching the posterior edge of the mesonotum; scutellum longer than wide, the surface the same as that of the remainder of the thorax, the two, oval, small, shallow foveæ slightly rugose, distinctly separated by a rather fine ridge; mesopleuræ smooth and shining, in places shagreened or coriaceous, especially centrally and anteriorly Abdomen: Almost black, piceous ventro-posteriorly; entirely smooth, naked except for a few hairs at the base, laterally, and the hairs on the ventral spine and valves; not quite as broad as long, not produced dorsally, the second segment covering about half the total area, only slightly produced dorsally, but with the ventral margin curved; edges of other segments more vertical; ventral valves at about a 60° angle. Legs: Brown-piceous, darkest on the coxæ, lightest at the joints and on the tarsi; finely pubescent; tarsal claws simple. Wings: Clear, finely set with hairs, margins not ciliate; veins light brown, rather fine, cross-veins and subcosta heavier; areolet moderate in size; cubitus reaching basalis; radial cell open; second abscissa of radius somewhat curved, first abscissa arcuate, hardly suggesting an angle. Length: 1.7 mm.

Galls (Pl. XXIV, Fig. 1).—Cells within the wood of small twigs, usually not distorting the stem, or producing hardly noticeable swellings. Each cell is elongate-oval, about 1.0 by 2.5 mm., with a shell-like lining, distinct from but hardly separable from the wood; the cells lie wholly within the wood, which is not particularly modified; often a hundred or more are closely crowded in dense clusters. Exit holes, cleanly circular, about 0.5 mm. in diameter, disclose the infestation. On twigs of Quercus Douglasii.
Range.—California: Galt.
Types.—Five females (all imperfect) and 12 pieces of infested twigs. Holotype female, paratype female, and galls in the collections of The American Museum of Natural History; paratype females and galls with the author; galls at Leland Stanford University and the U. S. National Museum. Labelled Galt, California; March 29, 1920; Kinsey collector.