Andricus fimbriatus, new species

Agamic

Host.--Quercus bicolor

Gall.--This fimbriate-cup gall on bicolor was well described by Riley in 1877 along with a similar one but protruding farther, from a smooth cup on Q. prinoides. Both have often been referred to in literature frequently under the names glandulus and glandulosus. The fly described as Andricus glandulus Beutenmueller, of which the author has a cotype, and associated with the above gall is a red species from an unknown gall. It belongs to the genus Callirhytis and is closely related to C. operatola — the agamic generation of C. operator (Osten Sacken).

Habitat. — The type material was collected at Wilmette, Illinois, September 1, 1917, when the galls were dropping to the ground. "When some of the galls were cut open just a year later about half still contained larvae and half pupae and adults. One fly emerged in cage March 25 and one April 18, 1919. On December 2, 1919, five living flies were cut out. Transformation thus occurs in fall and emergence in the spring and the emergence is distributed over two seasons. As the emergence is before flowering there must be an alternating generation in a vernal gall. In 1908 the galls had nearly finished dropping by September 9 and in 1912 they had all dropped by September 10. They have been seen also at Evanston, Kenilworth, and Glencoe, Illinois, and at Porter, Indiana. The herbarium at Shaw Botanical Garden, St. Louis, has a specimen from Kimmswich, Missouri, collected in 1860.

The writer has field notes on a similar gall on nine other white oaks of the eastern United States where the recess in which the gall rests is not fimbriate and the gall protrudes half its length or more. See plate 3, figure 12, on prinus [montana] and figure 13 on macrocarpa. As he has not been able to rear any of these as yet it is not known whether any or all of these are caused by the above-described species or which if any is glandulus Beutenmueller.

Andricus incertus

Fimbriate cup gall. A smooth elongated gall, 4 by 7 mm., partly imbedded in a fimbriate depression in the side of the acorn cup and slipping to the ground when mature in the fall. On Q. bicolor. Flies emerge the second and third springs Mar. 25-Apr. 18 and oviposit in buds of Q. bicolor. Alternating generation unknown.

Andricus incertus

Quercus bicolor
Acorn galls
Gall 6.6 by 4 mm, with a nipple at apex formed in a depression in side of cup surrounded by a fringe.

Quercus lyrata
Acorn galls
Gall in a fimbriate depression on the side of acorn cub, dropping in early Sept.

[Photo caption]
On Q bicolor. Galls drop in early Sept. and adults emerged the second and third springs in late March and April. A similar gall occurs on nine other white oaks where the recess in the cup is not fimbriate and the gall protrudes for half its length or more. None of these has been reared. A bit of cloth would have to be tied about an affected acorn to prevent loss of the gall when it matures and drops.

Andricus incertus Bassett

Andricus fimbriatus

The holotype of incertus was taken ovipositing in bud of Q. hicolor on April 22 at Waterbury, Conn., and is preserved in the Bassett collection in Philadelphia. In June 1921 S. A. Rohwer at my request took a paratype of fimbriatus to Philadelphia to compare with incertus and could see no difference. This species producing a gall in a fimbriate cup on acorn cup of Q. hicolor should henceforth be known as incertus Bassett. These galls have been noted at Washington, D. C. The alternating generation is unknown.

Andricus incertus n. sp.

No galls. One gall-fly taken ovipositing April 22, 1890, in buds of Q bicolor.