Callirhytis enigma, new species
Host. — Quercus rubra Linnaeus, Quercus catesbaei Michaux, Quercus myrtifolia Willdenow, Quercus texana Buckley.
Gall. — In clusters of as many as 150 at the base of young sprouts 4-10 cm. underground. Clusters are roughly spherical and may measure 2.5 cm. in diameter. The appearance of the fresh galls is unknown. The type flies are from a disintegrated cluster, and a fleshy layer had evidently rotted away, leaving a hard and brittle shell 4 by 6 mm., longitudinally ridged, with a wall about one-half a millimeter thick. (Plate 33, fig. 20.) The fleshy layer is evidently thin, for in the sandy soils of Florida it seems to dry down on the inner shell instead of decaying as in the more humid northern soils, and the ridges show through. The species was known to the writer years before an intact cluster was found, and it was not until flies were reared from these Florida galls, in 1919, agreeing with the types that the character and appearance of the cluster was known. The galls figured are from Q. catesbaei. (Plate 33, fig. 19.)
Habitat. — The type flies are from Winnetka, Illinois, where a dis- integrated cluster containing adults was found October 22, 1914, at the base of a young sapling of Q. rubra. Empty galls of this species were also seen at Ravinia and Highland Park, Illinois. Intact clusters of galls were collected at Madison, Florida, October 21, 1919, on Q. catesbaei. They then contained pupae, and adults were cut out De- cember 4, agreeing with the Winnetka specimens. Others were seen at Gainesville, Ocala, Marianna, and Jacksonville. The same species was found on Q. myrtifolia at Carrabelle, Florida, October 19, and at Daytona November 20, and both pupae and adults were found when cut open on December 3. Empty galls were seen on Quercus texana at Boerne, Texas. The United States National Museum has a single similar fly from Jacksonville and a gall cluster from Georgiana, Florida, both without date or host records; also an empty gall cluster from Ocean Springs, Louisiana, collected February 3, 1898, on "Q. 'phellos ?."
