Disholcaspis quercusmamma

Pointed bullet gall. Similar [to Disholcaspis quercusglobulus] but pointed at the apex, subclasping at base, often distorted by crowding and extending along the stem for several inches sometimes. Frequently on sprouts from stumps or on small trees in large numbers in the fall. On Q. macrocarpa and bicolor. Adults emerge Oct. 20-Nov. 10.

Disholcaspis mamma (Gill.)

This gall may be confused easily with the preceding [Disholcaspis quercusglobulus]. The distinguishing characters are a velvety surface and pointed apex. It usually occurs in large numbers and in variable sizes on the branches of the burr oak, Quercus macrocarpa.

Color: green, turning brown.

Holcaspis duricoria

H bassetti as compared with H duricoria, is rather larger and more irregular in outline. The teat-like projection is much heavier and longer in proportion to the size of the gall and appears to be a drawn-out portion of the substance of the gall, while in duricoria it is a small, hard pointed projection much resembling a spine in many cases, and often almost entirely wanting. In bassetti the substance of the gall is more corky and easy to cut. The central cell, as before stated, is at the base of the gall, and when the latter is removed the point of the cell can usually be seen protruding below. Before the gall is detached the central cell is situated with its greatest diameter perpendicular to the limb at the point of attachment of the gall. In duricoria the cell is situated at the center of the gall; it never protrudes from below when the gall is detached; and it always has its greatest diameter parallel with the limb at the point of attachment of the gall. The central or larval cells are also differently shaped. In duricoria the cell is egg-shaped, while in bassetti the end towards the twig is somewhat pointed, so that the cell is very much the shape of a plump apple seed with the point rounded off.

Disholcaspis mamma

Quercus bicolor, lyrata, macrocarpa
Stem galls, detachable
Pointed Bullet Gall. Green to reddish, darker at apex, covered with very short pubescence, in fall.

[Photo caption]
On Q bicolor. Also on Q lyrata, macrocarpa. Adult in Nov (IL)

Disholcaspis quercusmamma (Walsh and Riley), 1869.

Cynips quercusmamma
Holcaspis mamma
Diplolepis quercus macrocarpae
Holcaspis duricoria
Holcaspis duricaria
Cynips macrocarpae
Andricus macrocarpae
Andricus quercus-macrocarpae
Disholcaspis quercus-mamma
Disholcaspis quercusmamma

Hosts: Quercus macrocarpa, lyrata, bicolor

Range: throughout eastern and central North America, from southern Manitoba, east through New Brunswick, throughout the eastern USA, and as far south as northern Florida and eastern Texas. However, the range of D. quercusmamma potentially extends anywhere that potential host trees have been transplanted outside their native ranges, if the insects were also translocated (e.g., Edmonton and Fort Collins).

Disholcaspis mamma

Galls on Quercus macrocarpa are here recorded from the following localities: Mandan (H. F. Bain), N. Dak.; Walnut Grove (C. J. W.) and Becker (L. Haney), Minn.; Evanston, New Lenox, Glen Ellyn, and Moline, IL.; Corinth (C. Barracks), Iowa; Cedar Point, Kan.; Nebraska City, Nebr.; Surry (C. Chupp), and Waterloo, Ind.; Manistee, Mich., and Medina, N, Y. On Q. bicolor at Evanston, IL. On Q. lyrata similar galls yielding similar adults at Hoxie and Texarkana, Ark., and Poplar Bluff, Mo.

In the Chicago area the galls start about the middle or end of July and some are full grown by end of August, adults emerging in different years from October 20 to November 10. At Poplar Bluff galls contained pupae October 8 and adults emerged November 13- December 3. Brodie found the galls at Toronto on Q. macrocarpa, the adults emerging in 1896 from October 17 to November 6. Some lived until November 22, but they do not survive the winter. In order to determine the next season's galls he "put 25 females in a muslin bag tied around a couple of low branches of burr oak from which the leaves had fallen on November 10 and for some days noted them ovipositing. They stood upon the tops of the buds grasping them firmly, then curving up the abdomen they pushed the ovipositor between the scales of the buds and remained a few minutes but they do not place more than one to three eggs in a bud." On May 30, 1897, he found numerous galls, the petiole or midvein beginning to bulge. By July 1 they were full grown and adults emerged July 11-17. "These galls were similar in form and texture to galls of H. petiolicola from white oak, contained from 3-10 cells, the producers emerge in the same way as A. petiolicoIa. Producers sexual, sexes about equally numerous." So far as the writer is aware this is the first published indication of an alternating generation for a Disholcaspis — a genus whose species are all known by agamic females emerging in the late fall.

Cynips quercus mamma [new species proposed but not thoroughly described]

[footnote]

See Proc Ent Soc Phil III, p 639, note. The gall resembling the oak-bullet gall (Q globulus Fitch) which is there mentioned as occurring on Burr oak, has been since ascertained by us to be produced by a distinct species of Gall-fly from that which produces the oak-bullet gall. The gall itself has the same very remarkable internal structure, but differs externally in being somewhat rougher and in usually having a little nipple at its tip, whence we may call it the oak-nipple gall (Q mamma). The fly, like that of the oak-bullet gall, occurs only in the female sex. Thirty-eight specimens, all females, came out from galls of the same year's growth Oct 22 to Nov 7. It may be called Cynips q. mamma, as it is an undescribed species.