Pontania monile, new species

Gall. — Gall occurring on the leaves of willow. Collected at the mouth of the American Fork Canon, Utah, by Mr. E. A. Schwarz, June 29, 1891.

Smooth, globular, fleshy galls, 6 to 8 mm. in diameter, occurring from 2 to together in a row on the underside of the midrib of willow leaf. The area of attachment is about one-half the greatest diameter of the gall, and on the upper side of the leaf appears as a slight convexity. When closely placed, the galls lose somewhat of the spherical shape, but rarely grow together. The larva begins eating out the interior of the gall near the base, and is rather robust, 10 mm. in length, with light, resinous head and dark eye-spots; light, yellowish- white body.

An exactly similar gall, except occurring 1 or 2 together, is represented in the collection, bearing the label January 10, 1884, without locality. It was collected in a later stage of development, and the interior is completely excavated. In most cases the larva had abandoned the gall, issuing near the base. The specimens probably came from the Northwest. A gall similar to the last was also received from Mr. Lawrence Bruner, Robinson's Ranch, Wyoming, collected September 15, 1881, with the statement that it occurred on the leaves of Populus angustifolia. Examination of the leaves seems to indicate that they are willow rather than poplar, and the gall may be doubtfully referred to the type described above.

- Charles Lester Marlatt: (1896) Revision of the Nematina of North America, a Sub-family of Leaf-feeding Hymenoptera of the Family Tenthredinidae^©

Reference: https://www.biodiversitylibrary.org/page/52142981#page/123/mode/1up