Burnettweldia corallina (Bassett 1890), comb. nov.

Holcaspis corallinus
Disholcaspis corallina
Cynips corallina

Hosts: Quercus douglasii

[A picture of the gall is given on page 32 of the pdf]

Gall. (Fig 93). Detachable, monolocular gall occurring singly or in clusters of 2–4 at the base of leaf petioles. The gall is orange, yellow, or reddish when mature, 10–11 mm wide, with club-like, 2 mm long projections; in some galls the surface projections are reduced to rounded bumps or tubercles. The surface of the gall is delicately pubescent. Parenchyma of the gall is thick, hard, crystalline, reddish pink; the larval chamber thick-walled, oval, located at the gall base, above point of attachment. Young galls are yellow-green, growing directly from young stems, coated with velvety, whitish stellate pile. Over time a black sooty mould grows on mature galls, and they become hard and lignified (Burnett 1977, Russo 2006).

Biology. Galls develop in summer, mature in November; adults emerge aftersoon. Galls on Q. douglasii (Burks 1979, authors).

Distribution. USA: California (Burks 1979); San Joaquin Valley, CA (Burnett 1977)

Disholcaspis corallina

Pale yellowish, globular galls, about 12 mm. in diameter, found on the twigs of Quercus douglasii. The galls are pointed at the poles and the surface is roughened by irregular ridges, or bears short, blunt tubercles giving it the appearance of coral.

Habitat. Mt. Diabalo, California.

Weldia corallina, new combination

Holcaspis corallinus
Holcaspis corallina
Disholcaspis coralline
Cynips corallina

Gall: Monothalamous stem galls occurring singly or in clusters of 2-4 on Q douglasii, numerous on some trees; basically globular in outline, some spherical, others dome-shaped at apex and truncate at base above point of attachment; surface of mature galls usually studded with blunt peg-like projections; in some galls the surface projections are reduced to regular rounded bumps or tubercles; parenchymal zone thick, hard, crystalline, reddish-pink; larval capsule thick-walled, oval, usually located in gall base just above point of attachment; new galls yellow-green, growing directly from young stems, coated with velvety, whitish, stellate pile which weathers off at maturity; full-sized galls red or wine colored, old galls black; not deciduous. Horizontal diameter of 100 unparasitized galls, 10.8 mm.

Two basic types of epidermal sculpture are observed in galls, one form with short, peglike projections uniformly distributed over the surfaace of rather spherical galls, the other type with large, rounded pumps or tubercles externally, more prominent at the base of dome-shaped or mushroom-shaped galls. These differences appear to be geographically related with the former occuring from Fresno Co in central CA, northward around the San Joaquin Valley rim and in areas of 1000-2000 feet or more in elevation. Galls with rounded bumps or tubercles occur south of central Fresno Co on the western slopes of the Sierra Nevada Mountains as far south as Tehachapi at elevations between 1500 and 3500 feet. As with galls of other species in the group, differences in epidermal sculpture may result from differences in moisture available to growing galls, depending on the amount of annual rainfall, host species, soil type, drainage, and other factors.

Host: Quercus douglasii, durata, and garryana(?). It is possible that W corallina is hosted only by Q douglasii and its hybrid forms.

Range: around the margin of the San Joaquin Valley

[From key to galls, page 176 of the pdf]

1. Spherical or cone-shaped stem galls, usually with an apical projection or strong surface tubercles

2. Surface of mature galls deep red, studded with, more or less, uniform, blunt tubercles; parenchyma hard, crystalline; larval capsule basal; on Q douglasii and its hybrids.

Disholcaspis corallina

Quercus douglasii
Stem galls, detachable from the twig
Fig. 78. Rugose bullet gall. Dia.8.0 mm.

78. Q douglasii. Grace H Cole collected galls at Fair Oaks on Oct 20 and when examined on Nov 17 one had an exit hole in it and a living adult was in the box. This is the first record of a normal emergence date.

Disholcaspis corallina

This cynipid wasp induces round, monothalamous, orange, yellow, and reddish, detachable stem galls in summer on blue oaks.

Host:
Quercus douglasii

Holcaspis corallina Bassett

Holcaspis corallinus Bassett

Gall. (Plate IX, Figs. 13, 14.) On twigs of a species of dwarf oak (Quercus, sp.) Coral-shaped, rounded with the surface irregularly and thickly studded all over with short, stumpy projections which differ in size. Reddish buff-colored when fresh and blackish when old; covered closely with a velvety pubescence. Internally the gall is yellowish brown and contains a single, attached, larval cell. Diameter 7 to 10 mm.

Habitat. California.

The types are in the American Entomological Society and type galls in the American Museum of Natural History.