Dros perlentum Kinsey, 1937
Dros perlentum Kinsey (1937a: 51)
Dros petasum Kinsey (1937a: 52)

Gall (Figs. 5a-c): It takes the shape of a cup located on the underside of leaves. The basal stem is uniformly cylindrical (about 3mm in length); the anchoring area or basal part is slightly wider; the cup-shaped body (10 mm in diameter x 8 mm in height) expands abruptly from the stem; the upper edges of the gall are thick, which makes it retain the circular edge. The color of the gall is yellowish-brown or reddish.

Hosts: Quercus laeta, Quercus magnoliifolia Née, 1801, Q. obtusata, and Quercus opaca Trelease, 1924 (section Quercus).

Biology: Only the asexual form is known. The galls develop in May-June; adults emerge in June and July.

Distribution: Cited from the states of Mexico City (including Sta. Fe on Q. laeta), Jalisco, and Mexico (Kinsey 1937a; Lobato-Vila et al. 2019; García-Martiñón et al. 2018).

Dros perlentum, n. sp.
Agamic form

Gall. — The same as the galls of petasum. Basal stalk uniformly cylindric, slender, averaging 2.7 mm. in diameter; the cupped body of the gall expanding abruptly from the stalk; the base somewhat wider than the stalk, thin, plate-like; the upper edges of the gall broad, about 2. mm. in width; color yellowish-brown and red: up to 10. mm. in diameter and 8. mm. high.

Host. — Quercus macrophylla [magnoliifolia].

Range. — Jalisco; a locality 35 E of Aguascalientes, 7000’. — Probably restricted to northernmost Jalisco.

Life History. — Adults: April 15. This and D. petasum are the only described Mexican species with yellow-brown galls which have distinctly broadened, inrolled edges on the cup which is terminal on the body of the gall. The ranges of the two species are contiguous, the present species having been collected in the northeastern corner of the state Jalisco, in the narrow extension which lies between Aguascalientes and Guanajuato. Petasum occurs in more southern and western Jalisco. Both perlentum and petasum occur on Q, macrophylla.

Dros petasum, n. sp.
Agamic form

Gall. — The same as the gall of perlentum. Basal stalk uniformly cylindric, slender, averaging 2.7 mm. in diameter; the cupped body of the gall, expanding abruptly from the stalk; the base somewhat wider than the stalk, thin, plate-like; the upper edges of the gall broad, about 2, mm. in width; color yellow-brown and red; up to 9. mm. in diameter and 11, mm. high.

Host. — Quercus macrophylla

Range. — Jalisco: Guadalajara, 10 W, 6000 k Magdalena, 4 N, 4300' (galls). — Probably restricted to the central and southern portions of the state of Jalisco.

Life History. — Adults: March 3, 10, April 1, Most of the emergence in the first half of March. Petasum and perlatum are the only Mexican species of the complex with yellow-brown galls which have broad, inrolled, upper margins. Petasum has been recovered from Jalisco west of Guadalajara; perlentum was found in the northeastern corner of that state near Aguascalientes.

Dros perlentum, comb. rest. (=D petasum, syn nov)

[Photos of this gall appear on page 6 of the pdf]

Basal stem uniformly cylindrical, cup-shaped body abruptly expanding from the stem; the upper edges of the gall are thick, which causes a circular border to persist; yellowish-brown or reddish color.