Cynips (aggregata) tigrina, new species
agamic form

GALL.-Moderate in size, up to 28. mm., but averaging nearer 20. mm. in diameter, the globular body drawn out into a very short, abruptly truncate stalk at base; light yellow to pinkish or rosy tan, very conspicuously spotted and irregularly striped with rich purple, usually dusted with a bluish puberulence; occurring singly, rarely in twos or threes, attached to the main veins of the leaves. Figures 9, 86.

HOST.-Quercus nudinervis.

RANGE.-Guerrero: Taxco, 8 NE, 8000' (types). Possibly extending over a much wider area in Southwestern Mexico, but so far known from only the single locality in Northeastern Guerrero. Figure 84.

LIFE HISTORY..—Adults: March 18, 25. April 1, 2. The bulk of the emergence late in March and early in April.

The gall is spectacularly spotted with purple, and is unique in the complex in being located on leaves instead of on stems. This leaf gall provides the evidence that the stem-oviposition common in the complex was derived from leaf-ovipositing ancestors. See the introduction to the whole complex for a further discussion of the relation of this insect to the bulboides and dugèsi stocks.

Atrusca tigrina (Kinsey, 1936)

Figs 586–599

Synonymy
Cynips (aggregata) tigrina Kinsey, 1936: 167, female, gall.
Atrusca tigrina (Kinsey): Weld 1952: 316.

Types examined

HOLOTYPE female Cynips (aggregata) tigrina “Taxco 8NE Gro 8000’, Mex. Gall 1.7.32, 6 fms. 4.1.32”, “Q. nudinervis, Kinsey coll.”, red “Cynips tigrina, Holo- Paratype”, deposited in AMNH, NYC, examined by GM.
Three PARATYPE females “Taxco, 8NE, Gro 8000’, Mex., gall 1.7.32., 6 females 4.1.32”, “Q. nudinervis Kinsey coll.”, red label “Cynips tigrina Paratype”, deposited in the general collection in AMNH, NYC, examined by GM.

Gall (Fig. 599)

The gall is up to 28 mm, in average 20 mm in diameter, globular, with a truncate pedicel, light yellow to pinkish or rosy tan, conspicuously spotted and irregularly striped with rich purple, usually dusted with a bluish puberulence; singly, rarely 2–3 in one cluster, attached to the main vein of the leaf.

Biology

The asexual generation is only known to induce leaf galls on Q. magnoliifolia (= Q. nudinervis). Galls mature in late autumn – beginning of winter; adults emerge in March–April next year.

Distribution

Mexico: Guerrero.