Cynips quercus verrucarum

Neuroterus verrucarum var. pernotus

Neuroterus verrucarum

Neuroterus quercusverrucarum

Neuroterus flocossus

Neuroterus exiguissimus

Cynips verrucarum

Cynips flocossa

Cynipidae

Neuroterus

Quercus alba

Alabama

Arkansas

Connecticut

Delaware

Florida

Georgia

Illinois

Indiana

Iowa

Kansas

Kentucky

Louisiana

Maine

Maryland

Massachusetts

Michigan

Minnesota

Mississippi

Missouri

Nebraska

New Hampshire

New Jersey

New York

North Carolina

Ohio

Oklahoma

Pennsylvania

Rhode Island

South Carolina

Tennessee

Texas

Vermont

Virginia

West Virginia

Wisconsin

Ontario

Quebec

Quercus chapmanii

Quercus lyrata

Quercus macrocarpa

Colorado

Montana

New Mexico

North Dakota

South Dakota

Wyoming

Alberta

Manitoba

New Brunswick

Saskatchewan

Quercus margaretiae

Quercus michauxii

Quercus prinoides

Quercus sinuata breviloba

Quercus stellata

Cynipid galls of the eastern United States

The Gall Wasp Genus Neuroterus

Neuroterus quercusverrucarum (agamic)

Cynips quercus verrucarum n. sp.  

Quercus obtusiloba [stellata]. Post Oak. 

Small, round, pubescent, wart-like excrescences on the underside of the leaves. Diameter about 0.08. 

They occur in numbers on one leaf in the latter part of the summer ; when the leaf is dead, the wooly pubescence of these excrescences is pale ferruginous, but earlier in the season, it is I suppose, snow-white, as are similar excrescences on other oaks. 

On the Cynipidae of the North American Oaks and their Galls

Neuroterus exiguissimus n. sp.

Galls found in Autumn on the underside of leaves of Q alba, arranged along the sides of the midvein or principal veins, closely sessile but not easily separable from them, and showing an indentation in the lamina of the leaf where they grow, and a small, smooth elevation on the opposite side. They are hairy or coarsely flocculent, like the galls of N. floccosus B. The lateral diameter is about .10 of an inch ; the vertical .05. Denuded of the dense woolly covering the gall, which is the larval cell, is smooth, hemispherical (sometimes oval) and .03 in the lateral diameter. They chiefly affect the leaves at the ends of young oak branches. These leaves are generally curled and distorted, though this does not seem to result from the attacks of the gall insect. I have these galls from Providence, R. I., and Amherst, Mass., and for several years past I have found them quite abundant in Waterbury, Conn. They resemble, individually, the gall of N. floccosus B., but are smaller and are confined to the large veins of the leaf, mostly to the midvein, and they grow on Q. alba, while N. floccosus is found on Q. bicolor. All the gall-flies I have reared are females. 

New Species of North American Cynipidae (1900)

Neuroterus (Diplobius) verrucarum (Osten Sacken)
agamic forms 

[Kinsey gives lengthy series of varieties by host, region, and morphology now treated as synonyms of N quercusverrucarum:

[var exiguissimus](https://www.biodiversitylibrary.org/page/53512324#page/325/mode/1up) Bassett - Quercus alba; MA, RI, CT.

[var inficiens](https://www.biodiversitylibrary.org/page/53512324#page/327/mode/1up) Kinsey - Quercus breviloba; TX

[var macrocarpae](https://www.biodiversitylibrary.org/page/53512324#page/328/mode/1up) Kinsey - Quercus macrocarpa; TX, OK, LA

[var opacus](https://www.biodiversitylibrary.org/page/53512324#page/329/mode/1up) Kinsey - Quercus stellata, breviloba; TX, OK, LA

[var pulvinus](https://www.biodiversitylibrary.org/page/53512324#page/331/mode/1up) Kinsey - Quercus stellata; TX

[var restrictus](https://www.biodiversitylibrary.org/page/53512324#page/333/mode/1up) Kinsey - Quercus chapmanii, margarettae; FL, GA

[var verrucarum](https://www.biodiversitylibrary.org/page/53512324#page/333/mode/1up) Kinsey - Quercus stellata; DC, VA

Three of his varieties, var [minutissimus](https://www.gallformers.org/gall/767) on live oaks and vars [floccosus](https://www.gallformers.org/gall/4276) and pernotus (=floccosus) on Quercus macrocarpa and bicolor, are now recognized as valid species distinct from quercusverrucarum.]

GALL. — A minute cell covered with a flattened disc of wool. Monothalamous. Each gall a smooth, seed-like cell, hard, thin-shelled, entirely hollow, attached by a small point to a leaf-vein, separable, but the leaf depressed so at the point of attachment that the gall is not easily detached; the cell covered with a dense, whitish mass of wool which dries brown, the wool somewhat flattened, disc-shape, varying in diameter from 0.7 mm. in one variety to 3.5 mm. in another, averaging 2.5 mm. Attached to veins on the under surfaces of the leaves; indicated on the upper surfaces by a smooth, naked, circular, papilla elevation with a slight indication of a central point, this papilla however almost lacking in a couple of varieties. On leaves of white oaks except the chestnut oaks (figs. 32, 33). 

RANGE. — Ontario to Minnesota, Florida, and Texas. Apparently confined to the eastern half of North America. This very common species has developed varieties in which the insects are usually distinguishable only by slight differences in size, color, and size of the areolet. These differences would not be enough to warrant the recognition of distinct groups, except that they are very constant in large series representing several localities of a single faunal area, and are correlated to a large degree with host and distributional data. Nevertheless in some cases I have not been able to distinguish material from undoubtedly distinct faunal areas. The galls of the several varieties differ mostly in regard to average size. Many of the varieties are confined to single hosts in distinct faunal areas ; in a few cases a variety seems to occur on two closely related oaks or over two adjacent areas. Pulvinus is a variety with a very distinct gall but the insect is indistinguishable from opacus. The species is closely related to Neuroterus niger which is evidently a more primitive species. The degree of separability and the distinct form of the gall of verrucarum, its restriction to eastern North America, and its exclusion from the chestnut oaks, all suggest something of specialization. The best key characters for the insect of verrucarum are the small abdomen and the slightly and smoothly curved first abscissa of the radius; the eyes are smaller and the cheeks are wider than in niger. The known life history data are much the same for all of the varieties. The galls are first seen after mid-summer, in August further north, probably earlier further south; the larvae do not mature until late in the fall or early in the winter, then quickly becoming adults which remain in the galls on the dead leaves over winter, emerging in the early spring, March or earlier in the south to May further north. This is as much as is known of the species, the bisexual form not being known. It is probable that an obscure bud or flower gall, probably monothalamous, will prove to be the alternate of the agamic verrucarum. 



Neuroterus verrucarum

Quercus breviloba, chapmani, stellata
Leaf galls, integral
Compact woolly mass, 2 mm in dia by 1 mm high, in numbers on under side in fall.

Quercus margaretta
Leaf galls, integral
Scattered compact woolly masses 2 mm in dia on under side of leaf in fall.

[Photo caption]
Compact woolly mass 2 mm in dia by 1 mm high in numbers on under side of leaf of Q stellata in the fall. 

"Like Neuroterus verrucarum"

Quercus stellata
Leaf galls, detachable
Like Neuroterus verrucarum but detachable, with short hairs, with scarcely a trace on leaf above. Seen in MO, TX.

Neuroterus exiguissimus

Quercus alba
Leaf galls, integral
Hairy, brown, 2.5 mm, on under side in numbers along veins, sessile, leaf smooth above. In fall.

[Photo caption (no photo)]
On Q alba. Adults emerged the next spring in April (DC).

Neuroterus quercusverrucarum (Osten Sacken) 

Cynips quercus  verrucarum Osten Sacken 1861: 62. Females  and  galls  (types examined). 
Cynips verrucarum: Osten Sacken 1865: 354. 
Neuroterus  verrucarum: Ashmead 1885a: 296,  304. 
Neuroterus   quercusverrucarum: Burks 1979:  1075. 
Neuroterus exiguissimus Bassett  1900: 332. Females and galls (types examined). New synonymy. 
Cynips flocossa Bassett 1881 : 111. Females and galls  (types examined). New synonymy. 
Neuroterus  verrucarum var. pernotus Kinsey  1923: 74. 
Neuroterus flocossus:  Burks  1979:  1073

Biology.--Only  the unisexual  generation is  known. This species induces detachable leaf galls which are small, smooth, seed- like larval cells, hard, thin-walled, and covered with a dense flattened yellowish brown mass of wool  that dries brown. The gall is monothalamous, attached to the underside of the leaf by a small point to the leaf vein, separable,  but the leaf is depressed at the point of attachment. The average diameter of a gall is 2.0 mm by 1.0 mm high. The galls are usually numerous, covering the whole underside of the leaf and  are found on Quercus alba, Q. bicolor Willd., Q. chapmanii, Q. margaretta, and Q. stellata. Viereck (1916) also recorded Q. macrocarpa Michx. as a  host, but this  must be confirmed. Galls begin to develop in September (Weld 1959). According to Kinsey (1923), the galls  appear  after  mid-summer in August and the larvae do not mature  until late in the fall. Adults emerge the next spring in February to March.

Distribution.-Ontario, New York, New Jersey,  Connecticut,  west to Illinois, Oklahoma, Texas,  south to Florida. 

Descriptions of four new species of cynipid gall wasps of the genus Neuroterus Hartig (Hymenoptera: Cynipidae) with redescriptions of some known species from the eastern United States

Neuroterus quercusverrucarrum (Osten Sacken 1861)

Hosts: Quercus chapmanii

[Asexual generation detachable leaf gall found in the fall]

Using gall wasps on oaks to test broad ecological concepts

Quercus michauxii added tentatively as a host based on [this unconfirmed observation](https://www.inaturalist.org/observations/49260089), which is somewhat atypical for the species. 

Gallformers ID Notes