Dros picatum, comb. rest. (=D repicatum, n. syn.)

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

Basal stem conical, cup-shaped body expanding gradually from the stem; the upper edges of the gall are thin, which means that the gall does not retain a circular outline on the top; color varies between red and brown.

Galls large (up to 10 mm in diameter and 11 mm in height), never strongly conical

Dros picatum, n. sp.
Agamic form

Gall. — The same as the galls of periscele and repicaturn. Basal stalk tapered to a narrow point less than 2.0 mm. in diameter; the cupped body of the gall expanding gradually from the stalk; the base somewhat wider than the stalk, thin, plate-like; the upper edges of the gall about 1.7 mm. in width; color bright ox-blood to deep brownish red; up to Q mm, in diameter and 10. mm. high.

Host. — Quercus macrophylla,

Range, — Guanajuato: San. Felipe, 20 SW, 8000L Zacatecas: La Mesa, 7000’. — Probably confined to Q. macrophylla, but widespread wherever that oak occurs in Central Mexico, possibly from Zacatecas to Queretaro.

Life History, — Galls fresh, very sticky, December 7. Adults: December II. March 20. April 20, 25. Most of the emergence late in April,

There are two species of this complex represented in our collections from Guanajuato, and even from the one locality 20 miles southwest of San Felipe. These two species, picatum and repicatum are obviously host isolates, picadum being restricted to Q. macrophylla while repicatum is known from most of the other oaks of the region (L e. from the dwarfs, Q. jaralensis and Q, microphylla, and from the aborescent species, Q, sacame and Q. undaia).

Dros repicatum, n. sp.
Agamic form

Gall. — The same as the galls of periscele and picatum. Basal stalk tapered to a narrow point less than 2.0 mm. in diameter, the cupped body of the gall expanding gradually from the stalk, the base somewhat wider than the stalk, thin, plate-like; the upper edges of the gall about 1.7 mm in width; color bright ox-blood to deep brownish red; up to 7.5 mm. in diameter and 8.0 mm. high.

Host. — Quercus jaralensis, Q. mlcrophylla, Q. sacame, Q. undata. Not found on Q. macrophylla.

Range. — Aguascalientes: Pabellon, 20 W, 7000’, (Q. undata; also galls on Q. sacame). Zacatecas: La Mesa, 7000’ (Q. sacame). Guanajuato: San Felipe, 20 SW, 8000’ (Q. jaralensis). Leon, 20 NE, 9000’ (Q. jaralensis, Q. mierophylla). Probably found on all the white oaks except Q. macrophylla, throughout a wide area in Central Mexico, at least from Zacatecas to Queretaro.

Life History. — Adults: December 14. March 20, 30. April 10. May 10. Most of the emergence late in March and early in April.

The present complex is represented on Q, macrophylla in the state of Guanajuato by the species picatum. Dros repicatum is a host isolate occurring in the same area on most of the oaks other than Q. macrophylla) ie. on the dwarf oaks, Q. jaralensis and Q. microphylla, and the taller trees, Q, sacame and Q. undata. Although repicatum and picatum are host isolates in the same area in Guanajuato, repicatum is really closer to D. periscele from the eastern part of San Luis Potosi.