Neuroterus saltarius

Quercus bicolor
Leaf galls, detachable
Saucer-shaped, on under side in numbers in June. Leaf surface opposite is smooth, lighter in color. After dropping in August they bounce about for some time.

Quercus macrocarpa
Leaf galls, detachable
Small spangle in a cup-shaped depression on under side of leaf in numbers in fall and dropping out.

[Photo caption]
On Quercus macrocarpa. On Q bicolor. After galls drop in June they jump about on the ground for some time as do the related species, Neuroterus saltatorius in CA. Adults emerged the second spring in March.

Neuroterus saltarius, new species

Hosts: Quercus macrocarpa

Gall (fig 2) -- Small, seed-like bodies, inserted in cup-like depressions on the under surface of leaf and causing a prominent light-colored bulging on the upper side of the leaf opposite, often two or three hundred on a leaf, less numerous on the basal part of leaf blade. When growing the galls are greenish-white, somewhat globular, flattened above with a papilla in center and a raised rim, not pubescent. They start to develop in June and in July or August drop to the ground where they exhibit the phenomenon of bouncing about until the lodge in some crevice in the soil where they pass the winter. When detached a large scar is left on base of gall. During the winter the galls become tan-colored and somewhat compressed laterally, one measured 1.2 mm long by .9 mm thick and 1.1 mm high.

This gall seems to have been first described in 1876 by Riley who unfortunately applied to it the name of a California species with similar jumping habits. Under this name the eastern gall has been mentioned many times in literature and good figures have been published of it but up to the present no one seems to have reared the adult.

Habitat. — The types are from Hope, Ind. Galls collected on burr oak by C. J. Casey showed the bouncing when received at Washington June 26, 1923. These galls were placed in rearing and adults were cut out of them on December 5 and 12, and March 26. The writer had collected the galls in four different years at Evanston and Kenilworth, IL., but failed to rear them. At Medina, N. Y., they were full grown by June 30. Galls were received also from Ann Arbor (Pennington), Mich., and Corinth (Barracks), Iowa. They have also been reported in literature from Missouri and Minnesota. A similar gall occurs on Q. bicolor.