Femuros lusum Kinsey, 1937

Gall (Figs. 5f-g). These develop on thin branches from growth buds. They are unilocular, of compact and woody consistency when mature, in the shape of a cylindrical cup, 8–18 mm in length and 7–15 mm in diameter, composed of two subunits; contracted in the upper and lower third. The upper end is depressed with a continuous edge. The immature gall is greenish with a purplish edge, upon maturing it acquires a brown color; the surface is covered by a fine brownish pubescence that remains on the mature gall. The internal larval chamber is located in the contracted part of the gall; it is globular, with a hard wall connected to the gall tissue. The emergence hole is located within the upper depression.

Hosts. Quercus rugosa and Q. laeta (Quercus section).

Biology. Only the asexual form is known. The galls develop in May-June and by November they are mature; adults emerge from early March to early April of the following year.

Distribution. Cited for the state of Michoacán. This represents the first record for Mexico City (Santa Fe) and the first record on Q. laeta.

Femuros lusum comb. rest.

Femuros lusum, n. sp.
Agamic form

Gall. — Very large, cylindric, with the thin-walled top half of gall wide open or flaring, making the gall widely-open cup-shaped with a thick and solid base, the open cavity almost as wide as whole gall; outside of gall silvery to yellow-brown, young galls quite scurfy, older galls naked. Diameter of body of gall up to 15.0 mm., averaging nearer 11,0 mm., the flared top sometimes as much as 19.0 mm. in diameter; length up to 19.0 mm., averaging near 15.0 mm.

Host. — Quercus conglomerata [rugosa].

Range. — Michoacan; Morelia, 14 E, 7000’ (types). Possibly extending through the mountains of Michoacan and part of Jalisco,

The galls of lusum and perfectum are strikingly distinct, representing as extreme departure from the basic type of gall as one might readily conceive. In lusum the galls are scurfy, brown, very large, distinctly cylindric, with the cavity at top very large and broadly open, or even with its thin-walled boundaries widely flared open. The galls of perfectum are covered with a purplish-white scurf, of fair size, nearly spherical, with only a very small cavity at top which is more or less completely closed at the apex.