Biorhiza solita, n. sp.
Agamic form

Gall — Similar to that of B. pulchripennis. Light to rich brown, weathering darker; of medium size, up to 4.2 mm., averaging near 3.5 mm. in diameter.

Host. — Q. macrophylla [magnoliifolia] (types), Q. huematophlebia [magnoliifolia], Q. rhodophlebia [rugosa], Q. chihuahuensis, Q. sacame [arizonica], Q. undata, Q. reticulutam [rugosa], Q. potosina, Q. jaralensis [potosina], Q. microphylla. Apparently one species on all of these white oaks.

Range.— Jalisco: Guadalajara, lu W, 6000' (Q. macrophyda). Guadalajara, 25 S, 6000’ (galls, Q. haemafopldebia, Q. macrophyIla), Magdalena, 4 N, 4300’ (galls, Q. macrophylla). Sayula, 13 W, 7700’ (Q. rhodophlebia). Atequiza, 5 E, 0500’ (galls, Q. haematophlebia). Guanajuato: San Felipe, 20 SW, 8000’ (Q. chihuahuensls; also galls on Q. macrophyda, Q, juralensis). Leon, 20 NE, 9000’ (galls, Q. reticulata, Q. jaratensis, Q. microphyUa). Aguascalientes: Aguascalientes, 35 E. 7000 (Q. macrophylla; also galls on Q. poiosina, Q. undata). Pabelion, 20 W, 7000’ (galls, Q. sacame, Q. undata, Q. inacrophylla). Pabelion, 23 W, 3500’ (galls, Q. potosina, Q, sacame). San Luis Potosi: San Luis Potosi, 15 W, 7000’ (galls, Q. undata). San Luis Potosi, 15 W, 8000’ (galls, Q. potosina). Apparently widespread from San Luis Potosi to the far ends of Jalisco.

Life History. — Adults; in most cases probably emerging before the last week of November and December; stray emergence on March 2, 3, 11, and April 1.

Solita is the most widespread of me species in the complex, it appears to be one species from the southern corner of the state of San Luis Potosi, through Aguascalientes and Guanajuato, to the far ends of the state of Jalisco: and it is only a minor variation which spreads further east, from Queretaro all the way to Tamaulipas (sec the species soda}. It is apparently one species on all of the while oaks of the area — a total of ten oaks, including dwarfs, scrubs, and tall trees from which the galls have so far been recovered. The galls are often very abundant in these stands of oaks, and they are packed as tightly on the large-leaves of some of the tallest trees as they are on the small leaves of some of the alpine dwarfs. On a leaf of such a large-leaved species of oak as Q. macrophylla, one may find as many as three or four hundred galls, and extensive stands of scrub of this oak may have the leaves so heavily infested that the difference in color of the scrub as a whole is noticeable at considerable distances. All of our collections were made after the last Week of November, most of them in December, and the abundant emergence holes in the galls, as well as the small numbers of the later emergents, make it clear that most of the emergence occurs before the last week of November or early in December. Thus, in spite of our large collections of the galls, we have relatively few insects or solita, and larger series might show Local races or host isolates in what we are now taking to be one, widespread species.

Biorhiza socia, n. sp.
Agamic form

Gall. — Similar to that of B. pulchripennis. Light brown or even straw brown in color, sometimes richer brown; rather small galls, up to 3.7, averaging 2.9 mm. in diameter.

Host. — A tree form of Quercus microphylla; Q. reticulata [rugosa].

Range. — Queretaro: Queretaro, 28 N, 7300’ (Q. microphylla tree). — Hidalgo: Jacala, 7 NE, 5000’ (Q. reticulata; also galls on Q. repanda). Jacala, 5 W, 5800’ (galls, Q. reticulata). — Tamaulipas: Miquihuana, 25 NW, 8500’ (Q. cordifoUa). — Apparently widespread in the Eastern Sierra of .Mexico from Queretaro to Tamaulipas.

Life History. — Adults: December 10. January A March 15, 24. April 10. Most of the emergence apparently before the middle of January, stray adults emerging at later dates.

This species, socia, is an extension of P. solita. Socia is distinguished by having a smaller gall. Socia ranges widely over a southwestern portion of Mexico, from San Luiz Potosi to the far end of Jalisco. Socia (to judge on the basis of our limited material) ranges nearly as widely in the eastern Sierra, there being some two hundred miles between the localities recorded north of Queretaro and that northwest of Miquihuana in Tamaulipas. Although soda was bred from galls collected on the dwarf scrub, Q. cordifolia. in the mountains northwest of Miquihuana, the remarkable species zinzala is found in the same locality on the taller shrub, Q. Pringlei.

Biorhiza stelis, n. sp.
Agamic form

Gall. — Similar to that of B. pulchripennis. Rather light brown, often straw brown, darker only with age; of fair size, up to 4.7 mm., averaging near 3.5 mm. in diameter.

Host. — Quercus rhodophlebia [rugosa] (types’), Q, texcocana [deserticola], Q. Purpusli [rugosa].

Range. — Hidalgo: Pachuca, 7 N, 8700’ <Q. rhodophlebia, types). Mexico: Mexico City, 12 W, 8500’ (Q. texcocana). Mexico City, 25 E, TOGO7 (Q. texcocana). Jildtepec, 7 NW, 9500’ (galls, Q. Purposit). Apparently confined to the southern end of the state of Hidalgo, and to the mountains rimming the northern half of the Valley of Mexico. Replaced on Q, repanda in the same area by B. tanos, and replaced at the southern end of the Valley of Mexico by B. tricosa

Life History. — Adults: March 15, 20, 23, 24. April 10. The entire record thus between mid-March and mid-April.

The abundance of this species in the mountains rimming the northern half of the Valley of Mexico is so great that it was a simple matter to gather the very large series which we have in our collection. Unlike some of the other Mexican species of this complex, the insects of the present species do not emerge until March and April. stelis is confined to the taller oaks (Q. texcocana, Q. rhodophlebia) of the area. Under these taller trees, in the very same localities, on the low scrub oaks, Q. repanda, there is a very similar species, B. tanos of this same complex.

Biorhiza tarasco, n. sp.
Agamic form

Gall. — Similar to that of TT pulchripeofiis. Light yellow brown, of moderate size, up to Id im, averaging nearer 3.5 mm. in diameter.

Host. — Quercus conglomerata [rugosa]

Range. Michoacan: Morelia, 14 E, 7000J (types). Possibly restricted to a portion of the mountains of Michoacan.

Life History. — Adults: March 15, 25. April 10.,

In all other characters the species is typical of the complex, and its gall is indistinguishable from the galls of the other species of more southern Mexico. There can be no question that tarasco is one of the links in this complex.

Biorhiza tricosa, n. sp.
Agamic form

Gall. — Similar to that of B. pulchripennis, Rather light brown, often straw-brown in color, darker only with age; of moderate size, up to 4,0 mm., averaging 3.0 mm. in diameter.

Host. — Quercus rhodophlebia [rugosa] (types), Q. texcocana [deserticola]. Probably on all white oaks, except the low dwarfs in the area.

Range. — Mexico: Mexico City, 20 S, 9200'’ (Q, rhodophlebia, types). Mexico City, 17 S, 8200’ (Q. texcocana). Apparently confined to the southern end of the mountains rimming the Valley of Mexico.

Life History. — Adults: March 2, 10, 24, 30.

Biorhiza ulcus, n. sp.
Agamic form

Gall. — Similar to that of B. pulchripennis. Light to medium brown, of moderate size, up to 4.0 mm., averaging near 3.5 mm. in diameter.

Host. — Quercus nudinervis (types); Q. macrophylla. [both magnoliifolia]

Range. — Guerrero: Taxco, S NE, 8000' (Q, nudinervis, Q. macrophylla). Apparently confined to a northeastern portion of the .state of Guerrero.

Life History. — Adults: March 20.

- Alfred Kinsey: (1937) New Mexican gall wasps (Hymenoptera, Cynipidae). II^©