Neuroterus niger var. perminimus

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 bicolor

Nova Scotia

Neuroterus perminimus (sexgen)

Neuroterus perminimus [males and females reared, sexgen]

This is the smallest species from which I have ever reared any gall-flies. They lie imbedded in the lamina of white oak leaves, and show on both sides, but more distinctly on the upper side. They are oval, pustule like bodies, only .04 long, .03 wide and .03 deep. I have only met them in a limited locality in Rockport, Ohio. In some cases two hundred can be counted on a single leaf of ordinary size. Small as they are, they are so infested with parasites that comparatively few true gall-flies ever reach maturity. I have reared a few of both sexes. The galls reach their growth about June 25th, and the flies hatch out before July 10th. 

Note. — I have received within a week fresh galls of this species, but the flies had nearly all escaped on their arrival, June 28, 1900. 

New Species of North American Cynipidae (1900)

Neuroterus perminimus

White oak
Leaf galls
pustulate, abundant. 

Insects affecting park and woodland trees

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.

The North American Species of Neuroterus and their Galls

Neuroterus perminimus

The galls of this species are scarcely 1 mm. long and 1 mm. wide and 1 mm. deep. They lie embedded in the lamina of white oak leaves, are pustule-like in form, and oval and apparent on both sides of the leaf, though more distinctly on the upper than on the under side. As many as two hundred of them may be found on a single leaf of ordinary size. Since many of the individuals become infested with parasites, very few of the hosts ever reach maturity. The galls mature about the 25th of June and the imagos hatch out before July 10th in Ohio. 

Guide to the insects of Connecticut. Part III. The Hymenoptera, or wasp-like insects of Connecticut

Neuroterus niger variety perminimus Bassett bisexual form

Neuroterus perminimus
Neuroterus niger (in part)

GALL. — Small, oval, rather elongate, with sharply-defined boundaries, without a trace of a central point on the upper surface. On Quercus alba. 

RANGE. — Ohio: Rockport (Bassett). New York: New York City (Beutenmuller). Probably confined to a more northeastern part of the United States. 

Bassett recorded mature galls on June 25, with adults emerging before July 10 in one year, and before June 28 in 1900. I have collected galls from the typical host, Q. alba, at Forest Hills, Massachusetts, which appear to belong to an undescribed variety, but insects and galls in The American Museum of Natural History, from Q. alba in New York City appear to agree with the types. Varieties in this species are so similar that these records must not be trusted too fully for the definition of faunal areas. Beutenmuller made this a synonym of niger, altho even the published descriptions show that the two are distinct. On the same page, however, he described variety papillosus as a distinct species, — which is typical of the inconsistencies with which related things have been treated. 

The Gall Wasp Genus Neuroterus

Neuroterus perminimus

Cells separate, numerous, elliptical, 1-2 mm long, showing on both sides of the leaf but more distinct on upper. On Q alba in June [sexgen] and similar galls in the fall [agamic]. Flies emerge from the overwintering galls April 1-23.

Cynipid Galls of the Chicago Area

Neuroterus perminimus sexgen

Quercus alba
Leaf galls, integral
Similar [elliptical parenchyma thickenings 1 mm long] but larger lighter colored galls, single or few in number of leaf in spring when leaf is 2-3 in long and producing male and female in April may be the alt gen.

[Agamic generation also listed on Q bicolor]

Cynipid galls of the eastern United States