Neuroterus vesicula (sexgen)

Neuroterus affinis (sexgen)

Neuroterus perminimus (agamic)

Neuroterus niger (agamic)

Neuroterus perminimus (sexgen)

Neuroterus bassettii (sexgen)

Neuroterus quercusbatatus (sexgen)

Neuroterus quercusbatatus (agamic)

Neuroterus quercusbatatus (agamic) (q-bicolor)

Neuroterus quercusbatatus (sexgen) (q-bicolor)

Neuroterus clarkeae (sexgen)

Neuroterus pallidus (sexgen)

Andricus longipennis (sexgen)

Neuroterus papillosus (sexgen)

Neuroterus umbilicatus (agamic)

Neuroterus consimilis (agamic)

Neuroterus gillettei (sexgen)

Neuroterus vesiculus

Cynips vesicula
Cynips affinis
Neuroterus vesicula
Neuroterus affinis

Gall. In the buds of white oak (Quercus alba), dwarf chestnut oak (Quercus prinoides) and swamp white oak (Quercus platanoides [bicolor]), usually partly hidden in the scales of the bud, sometimes standing out round and free like a blister on the twig. Monothalamous, round, thin-walled and of a dark brown or greenish brown color, sometimes with grayish spots. In size it is only large enough to hold the larva within.

Habitat. CT, NY, NJ, IL, MI, IO

The galls of this large species of gall-fly are half-grown in the autumn and develop so rapidly in the spring that the insects come out just as the leaves begin to expand. I can find no differences between the adults and galls of N affinis and vesiculus, and they are, as surmised by Bassett, one and the same species. I have taken the galls in the vicinity of New York late in April. The flies begin to emerge about May 6.

Neuroterus niger

Neuroterus nigrum Gillette
Neuroterus niger Dalla Torre and Kieffer
Neuroterus perminimus Bassett

Gall. In numbers imbedded in the soft parts of the leaf of burr oak (Quercus macrocarpa) and white oak (Quercus alba). Monothalamous. Rounded or blister-like bodies protruding on both sides of the leaf, but somewhat more distinctly on the upper side; on the under side it has a minute nipple. Diameter 1-1.75 mm.

Habitat: MI; OH; IO; IN; IL; NY; NJ; PA

I fail to find any differences between the flies and galls of N niger and N perminimus, and I consider them one and the same species. The galls of N niger occur on burr oak (Q macrocarpa) and those of N perminimus on white oak (Q alba). The species is double brooded, the first brood emerges early in spring from galls of the previous year's growth, and the second brood appears during the latter part of June and early in July from galls formed by the first brood in May and June. The galls of the latter reach maturity late in August and in September.

Neuroterus pallipes Bassett

Neuroterus bassetti
Neuroterus pallidipes

Gall. On the midrib or principal veins of the leaves of white oak (Quercus alba) in May. Monothalamous. Small, oval, thin-walled swellings covered with a dense brownish pubescence. The affected leaves become distorted and dwarfed.

Habitat: MA, NY, NJ

Neuroterusbatatus (Fitch).

Cynips quercus batatus
Cynips q. batatus
Cynips batatus
Neuroterus batatus

Gall. On the terminal twigs of young white oak (Quercus alba). Polythalamous, hard, woody, uneven swellings, often resembling a potato in shape. They are usually much longer than broad, and often covered with a glaucous bloom. Green in summer and brown in winter.

Habitat. Canada; New England and Middle States southward; Ohio; Illinois; westward to Colorado

There are two annual generations of Neuroterus batatus. The first brood appears early in May, from galls of the preceding year's growth, and the second brood in June, from green galls. The second brood oviposits in the galls from which they were produced. Mr. Bassett states that he reared thousands of Neuroterus batatus of both generations, for a series of years, and always with the same results. The early summer brood from the leaf galls was always made up of both sexes in nearly equal numbers, while the brood from the late summer galls came out in the spring, just as the leaves began to appear, and were all females.

Neuroterus batatus (Fitch).

Cynips quercus batatus
Cynips q. batatus
Cynips batatus
Neuroterus batatus

Habitat. Canada; New England and Middle States southward; Ohio; Illinois; westward to Colorado

There are two annual generations of Neuroterus batatus. The first brood appears early in May, from galls of the preceding year's growth, and the second brood in June, from green galls. The second brood oviposits in the galls from which they were produced. Mr. Bassett states that he reared thousands of Neuroterus batatus of both generations, for a series of years, and always with the same results. The early summer brood from the leaf galls was always made up of both sexes in nearly equal numbers, while the brood from the late summer galls came out in the spring, just as the leaves began to appear, and were all females.

Neuroterus obtusilobae (Karsch)

Diplolepis q. obtusilobae
Neuroterus obtusilobae

Gall. On the tip of the twigs of post oak (Quercus minor [stellata]). Polythalamous. Irregularly rounded or ovate with aborted leaves. Hard and woody with gray brown tint. Inside are many larval chambers.

Habitat: Dallas, TX

Neuroterus noxiosus (Bassett)

Cynips noxiosa
Neuroterus noxiosus
Neuroterus noxiosa

Gall. Winter form. (Plate IX, Figs 1-7 [Beutenmuller's Figure 7 seems to clearly depict the sexual generation, so it is included in that page rather than this one]). On the terminal twigs of swamp white oak (Quercus platanoides [bicolor]). Polythalamous. Hard and woody swellings varying greatly in shape and size, but usually tuber-like. Internally there are numerous larval cells. Length, 5 to 100 mm. Width, 4 to 25 mm.

Habitat. New England and Middle States westward to Iowa

This species is double brooded, the first brood appearing in May from the large woody galls of the previous year's growth, and the second brood in June from twigs formed on the leaves and tender twigs.

Neuroterus noxiosus (Bassett)

Cynips noxiosa
Neuroterus noxiosus
Neuroterus noxiosa

Gall. Vernal form. (Plate IX, Fig 8 [Beutenmuller's Figure 7 is included here as well; it also clearly seems to depict this summer form despite the caption]). The gall is an enormous development of the mid-rib on the petiole of the leaves. It is green, succulent and irregular in shape. The blade of the leaf becomes dwarfed and curled, and after the galls mature the leaf becomes shriveled and dried.

Habitat. New England and Middle States westward to Iowa

This species is double brooded, the first brood appearing in May from the large woody galls of the previous year's growth, and the second brood in June from twigs formed on the leaves and tender twigs.

Neuroterus clarkeae sp. nov.

Gall On the edges of the leaf of white oak (Quercus alba) in May. Monothalamous. Light brown, bud-like and covered with short wool. It is thin-shelled, fragile, and contains no separate larval cell. Length 2-3 mm.

Habitat: MA

The flies emerge during the latter part of May and early in June.

Neuroterus pallidus Bassett

Gall. In dense clusters at or near the ends of the aments of swamp white oak (Quercus platanoides [bicolor]), early in spring. Monothalamous. Round, smooth, and unevenly globular. Pale faded wood color and of a fine soft cellular consistence. They are fragile and may be easily crushed.

Habitat: NY, NJ, CT

A distinct species readily known by its pale color. The gall is also very characteristic and may be easily known from other species found on the sterile flowers of the oaks.

Neuroterus longipennis Ashmead

Hosts: Quercus laurifolia

Gall: On the petiole of the leaf or surrounding the base of new shoots of laurel oak (Quercus laurifolia), in May. Small, oblong, irregular, woody swellings, measuring from 8 to 9 mm in length and 3.5 to 4 mm in diameter.

Range: FL

Neuroterus papillosus sp. nov.

Gall. (Plate X, Fig. 2.) In numbers on the leaves of swamp white oak (Quercus platanoides [bicolor]) in June. Monothalamous. Elongate oval, blister-like bodies protruding on both sides of the leaf, and without a nipple on the under side. Length about 1 mm.; width about .75 mm.

Habitat. Bronx Park, New York City.

The gall is somewhat similar to that of N. niger, but is smaller, and lacks the nipple on the under side. The flies emerge during June and early in July, from galls produced in May. The species is undoubtedly double brooded.

Neuroterus umbilicatus

Gall. (Plate XIII, Fig. 7.) In great numbers on the underside of the leaves of swamp white oak (Quercus platanoides [bicolor]) in August and September. Monothalamous. Small, circular, flattened and concave, with a minute conical elevation in the centre of the concavity. Beneath the conical elevation lies the minute larval cell.Brown and covered with minute hairs. The galls are easily detached, but leave an indentation which is seen as a flattened elevation on the upper side of the leaf.Diameter, 1 to 1.50 mm.

Habitat. Canada (Ontario); Connecticut; New York; New Jersey; Pennsylvania; Illinois.

Neuroterus consimilis 

[males and females described]

Gall. On the young terminal twigs of white oak (Quercus alba) in midsummer. Polythalamous. Hard and woody, irregularly rounded with aborted buds and leaves. It is a greatly fore-shortened and enlarged branchlet and measures from about 4 to 12 mm in diameter. 

The figure of the gall was made from one of the type specimens.

Neuroterus gillettei Bassett

Gall. On the petioles and mid ribs of the leaves of post oak (Quercus minor [stellata]). Polythalamous pustule-like and quite irregular in shape and size. When dry the galls are much shrunken and distorted.

Habitat: CT, NJ

The North American Species of Neuroterus and their Galls