Holcaspis rubens, n. sp.

Galls.--The galls are globular, from 10-14 mm in diameter, composed of a dense corky substance, each with a single larval cell that is easily detached from the surrounding portions, attached singly to small twigs. They have either a smooth or rough exterior, and are of a light straw color, usually considerably tinted with red. They resemble very closely the galls of Holcaspis rugosa Bass [Disholcaspis quercusglobulus]. The flies, however, are very different.

Location: CO

The flies began to emerge from the galls October 20th.

Disholcaspis rubens

Quercus arizonica, oblongifolia, toumeyi, reticulata [rugosa], gambelii, subturbinella [turbinella]
Stem galls
Detachable
Fig 58.

Disholcaspis rubens
Bullet-gall wasp
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Hosts: Quercus arizonica, oblongifolia, turbinella

Galls measure 10-15 mm in diameter and have either a smooth or slightly rough surface covered with sparse, crusty, tiny patches of three-forked hairs.

Holcaspis rubens Gillette

Gall. (Plate VII, Figs. 8, 9.) Singly or in clusters on the twigs of oak (Quercus undulata). Globular and composed of a dense corky substance, containing a single larval cell that is easily detached from the surrounding portions. Smooth or rough externally and of a light straw color, usually tinted with red. Diameter 10 to 14 mm.

Habitat. Colorado.

The gall very much resembles that of Holcaspis globulus but the flies are very different. The types are with Prof. C. P. Gillette and in the American Museum of Natural History.