Osten Sacken did not feel certain of the specific differences of futilisand of papillatus; the main reason for which the two have been kept distinct is the reddish ring sometimes found around the galls called papillatus, and the different host plants of the two. I have compared the types of the two species and believe them to be identical. At the most, papillatus may be a host variety of futilis. As far as I can discover, the female of this species has not been previously described. It is quite variable as to shade of coloring.
The galls of futilis are first discernible about the middle of May, and are then to be found often very abundantly, on the white oak especially, sometimes occurring in numbers on a single leaf. The galls are at first so succulent that they are not easily bred; they should be gathered late in June and be placed directly on moist sand. The adults emerge from the last of June to the middle of July, leaving the empty galls now dry, hard. and brittle. The insects are positively geotropic and, after copulation, oviposit in the bark of the roots or the bases of the trunks of the white oaks.
Andricus futilis form radicicola (Dalla Torre)
Plate XXX, Figure 27
Callirhytis radicis (non Fabricius, 1798) Bassett, 1889, Psyche, V, p. 237. Dalla Torre and Kieffer, 1902, Gen. Ins., Hymen., Cynip., p. 66. Smith, 1910, Ins. N. J., p. 601. Dalla Torre and Kieffer, 1910, Das Tierreich, XXIV, p. 571. Felt, 1908, N. Y. State Mus. Bull., CC, p. 54.
Andricus radicicola Dalla Torre, 1893, Cat. Hymen., II, p. 95.
Andricus (Callirhytis) radicis Vireck, 1916, Hymen. Conn., p. 426.
Female.—Bright rufous and darker rufo-piceous; mesopleurae mostly aciculate with some smooth and shining areas; abdomen with a ring of dense, whitish hairs at the base; areolet of moderate size. Head: bright rufous to dark piceous, slightly darker on the vertex; tips of mandibles piceous; very finely rugose, the face from the bases of the mandibles to the tips of the jaws densely hairy, rest of the head finely pubescent;' antennæ 14-jointed, remarkably short, uniformly yellowish rufous or rufous, or somewhat darker distally, densely hairy. Thorax: bright reddish to reddish brown or dark piceous, variable; mesonotum brightest in the center toward the scutellum, densely rugoso-punctate, somewhat striate toward the sides; parapsidal grooves continuous to the pronotum, convergent toward the scutellum, deep, hardly smooth; median groove deep at the scutellum, traceable beyond the middle of the mesothorax to the pronotum; anterior parallel lines close together, smooth, extending half-way to the scutellum; lateral lines smooth, two-thirds the length of the mesothorax, approaching the parapsidal grooves anteriorly. Scutellum almost circular, brighter rufo-piceous, irregularly rugose, the two distinct fovea at the base smooth; pronotum piceous, rufous anteriorly, rugose, hairy; mesopleuroe piceous black, mostly aciculate, smooth and shining along the posterior and the ventral edges; bright rufous at the bases of the wings. Abdomen: bright rufo-piceous, brighter basally; smooth and shining, two lateral patches and a ring of dense, whitish hairs at