Andricus fulvicollis form bicolens, new name
Plate XXXI, Figure 33
Dryophanta erinacei Triggerson, 1914, Ann. Amer. Ent. Soc., VII, pp. 4-7, P1. I, fig. 4, P1. II, figs. 7, 9, 10, P1. iii, figs. 21-29, P1. ix, fig. 70.
Cynips erinacei Felt, 1918, N. Y. State Mus. Bull., CC, p. 75.
Female. Generally piceous black; the parapsidal grooves not reaching the pronotum, lateral grooves broad and shallow, mesonotum otherwise about smooth, first abdominal segment only one-third tha length of the abdomen. Head: black, rough, face sparsely hairy, mouth-parts yellowish brown; head not broadened behind the eyes; cheeks not half as long as the eyes; antennae brown, lighter basally, hairy, 14-jointed, the first two segments considerably stouter than the following. Thorax: piceous black to black, me-onotum almost smooth, slightly roughened, coriaceous to finely rugose anterior of the parapsidal grooves; parapsidal grooves distinct, continuous almost but not entirely to the pronotum; median groove and anterior parallel lines lacking; lateral grooves broad and shallow, two-thirds the length of the pronotum; scutellum black, somewhat angulate in outline, finely rugose and finely hairy, with two, small, shallow, not smooth, divergent fovea at the base; pronotum and mesopleurae almost but not entirely smooth. Abdomen: piceous or brownish black, lightest basally, almost smooth, the second segment only about onethird the length of the whole abdomen. Legs: clear amber-brown, hairy, the coxæ darker brown, the tarsal claws simple, brownish black. Wings: tinged with yellowish, the veins light brown; areolet rather large; cubitus fainter than other veins but continuous to the basal vein; the radial area open; first abscissa of the radius angulate, slightly and limitedly clouded, the angle about 135°. Length: 1.7-2.0 mm.
Male.—Similar to the female; generally more brownish piceous; antennæ 15-jointed; legs lighter yellowish brown; abdomen smaller, petiolate; length, 1.5-1.7 mm.
[Redescribed from Illinois material bred by Mr. Lewis H. Weld.]
Galls.—Small, thin-walled, elongate egg-shaped galls (Fig. 33), within the bud-scales. The galls are about 2-3 mm. long, all but microscopically smooth, monothalamous, thin-walled, yellowish brown, without a separate or even distinct larval cell; sometimes two or three galls will develop in the same bud-scale and become fused. In the bud-scales or ("bicolens") on the terminal portions of leaf and flower buds of Quercus alba.
Types.—?
In 1914 C. J. Triggerson reported from the Entomological Laboratory of Cornell University an account of the life history of this species, together with a study of its parasites and inquilines, and questions concerning the stimulus for gall formation.. The observations on the life history of this wasp are more complete, and the evidence concerning the alternate generations more definite than for any other species of American cynipid, to (late. Branches with buds in which the agamic form had oviposited were brought into the laboratory, where the adults of the second generation were bred from the galls. Oviposition of this generation was observed both in the laboratory and in the field, and later
