Cynips gemula

Cynips fulvicollis var fulvicollis form pallipes

Dryophanta pallipes

Diplolepis pallipes

Philonix pallipes

Diplolepis gemula

Cynipidae

Acraspis

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

Quercus macrocarpa

Colorado

Montana

New Mexico

North Dakota

South Dakota

Wyoming

Alberta

Manitoba

New Brunswick

Saskatchewan

Quercus margaretiae

Quercus michauxii

Quercus montana

Quercus prinoides

Quercus stellata

Cynipid galls of the eastern United States

The Gall Wasp Genus Cynips

North American species of Dryophanta and their galls

Acraspis gemula (sexgen)

Cynips gemula, n. sp.

This species is a recent discovery of mine, having escaped detection on account of its early appearance and minute size. The gall is found in the centre of both the flowering and leaf buds of Q prinoides. It is fully developed when the sterile flowers of this species of oak are in bloom. Only one gall is found in a single bud. It is exactly like an ordinary acorn in shape, having a truncate base and a cone-like extremity with a sharp point at the apex. It is a dull blackish color, and only .1 of an inch in length and 0.05 in diameter. It contains but one larva. When the gall happens to be in a leaf bud it is often found at the summit of a young branch one or two inches long, so rapid is the growth of the tree at this season. In the flower buds it is often nearly hidden in the surrounding bud scales. The insects appear in both sexes about the middle of May. 

New Cynipidae (1881)

Dryophanta pallipes n. sp.

Galls.--The rapid Spring growth of thrifty young white oak shoots is sometimes suddenly checked by the appearance of this gall at their apex. The gall does not prevent the developed of the leaves below it, but immediately surrounding its base half a dozen of more brown, thread-like bodies from three-fourths of an inch to an inch and a half in length appear. Occasionally two or more of these are narrowly strapped in shape, and suggest that they are all undeveloped leaves. The gall, a mere larval cell at the center of this cluster, is blackish brown, thin shelled, oblong-oval, 0.9 of an inch in length and 0.6 in diameter. The insect emerges from the apex of the cell, leaving it resembling an eggshell with the end removed. This is a rare species, though I have found it in a certain locality several years.

CT, sexgen

New Species of North American Cynipidae (1900)

Dryophanta pallipes

Gall: Among the buds of thrifty young shoots of white oak (Quercus alba) early in May. The gall is oblong oval, thin-shelled and of a blackish brown color. It does not prevent the developed of the leaves below it, but immediately surrounding its base half a dozen or more long, brown thread-like bodies appear. The fly emerges from the apex of the cell, leaving it resembling a miniature egg-shell with the end removed. Length about 2.5 mm; diameter about 1.5 mm.

Habitat: CT, NY, NJ, PA

The flies emerged from the gall during May.

Dryophanta pallipes

Oblong, oval, thin-shelled, blackish-brown galls among the thrifty young buds and surrounded by six or more long, brown, threadlike bodies, length 2.5 mm, diameter 1.5 mm, on Q alba.

Key to American Insect Galls

Diplolepis gemula

Collected galls on Quercus alba at Winnetka, IL., on June 9, 1917, when most of the flies had already emerged. Galls at Ravinia contained pupae on May 23, 1919. A similar gall exists on bicolor and macrocarpa in the Chicago area and in the South on prinus, stellata, margaretta, and montana. 

Field notes on gall-inhabiting cynipid wasps with descriptions of new species

Cynips fulvicollis variety fulvicollis
bisexual form pallipes (Bassett)

Dryophanta pallipes
Diplolepis pallipes

GALL. — A rather elongate but still broadly egg-shaped cell with one end (the base) truncate, flat; reddish-brown and dark brown in color; the surface all but microscopically smooth ; the cell wall thin, hard and brittle, occasionally with more than one layer (as several bud scales become involved in the gall); entirely empty, without a separate larval cell; up to 3.5 mm. in length. Buried inside otherwise unmodified buds, or deforming and dwarfing clusters of leaves which become slender and thread-like about the gall; on Quercus alba. Figure 231.

RANGE. — Probably the same as that of the corresponding agamic form [this seems to be what we know as Philonix nigra] which occurs everywhere on Q. alba, from Massachusetts to Iowa and the Ohio River Valley (fig. 41). The bisexual form known definitely only from: Connecticut: Waterbury (Bassett, types). New York: state (acc. Beutenmiiller 1911). New Jersey: state (acc. Beutenmiiller 1911). Pennsylvania: state (acc. Beutenmiiller 1911). Indiana: Charlestown (E. W. Spieth in Kinsey collection).

These bisexual insects have been previously known only from Bassett’s very scant collection and from Beutenmuller’s records for which I have not seen material. I have secured 16 insects and numerous galls from southern Indiana by bagging large numbers of unopened buds of Q. alba in the early spring.

The date of appearance of the adult insect will vary as the latitude and season may affect the development of the buds of the oaks in the region. In southern Indiana adults were emerging from the galls on April 22 and May 1 in 1927. Bassett did not find the galls appearing in Connecticut until early May, while the insects emerged later in May. This insect has gone uninterpreted since Bassett's original discovery, but the following considerations now seem to lead to our conclusion that this is the bisexual form of no less common an insect than Cynips fulvicollis fulvicollis.

Pallipes is undoubtedly the alternate of some eastern American species of agamic Cynips for which at least some variety is already described. No Eastern species of Cynips (as categories are used in this paper) has been added to our list since 1882, altho new varieties are still being discovered. 

The only eastern American Cynips left for consideration as a possible alternate of pallipes is some variety of fulvicollis. Fulvicollis and pezomachoides are the only Cynips common on Q. alba in the northeastern quarter of the United States. 

[Cynips gemmula (link in text)](https://www.biodiversitylibrary.org/page/53516882#page/363/mode/1up)
bisexual forms

GALL OF BISEXUAL FORMS.— A thin-walled, egg-shaped cell, occurring singly in the buds of the chestnut oaks. Known for only a single variety, so see the description for variety gemmula bisexual form gemmula. 

[Cynips gemmula variety gemmula](https://www.biodiversitylibrary.org/page/53516882#page/371/mode/1up)
bisexual form gemmula

Cynips gemula
Dryophanta gemula
Diplolepis gemmula

GALL. — A small, thin-walled, elongate, egg-shaped cell in a bud. Monothalamous, about 2.0 to 3.0 mm. long, regular in form, nearly egg-shaped but somewhat more elongate, pointed apically, truncate at base; microscopically roughened; older galls dark brown to blackish. Very thin-walled, brittle when dry, without a distinct larval cell. Singly, deep and nearly hidden in the leaf or flower buds, or at the apices of young stems or on the main stems of the staminate flowers and surrounded by a few deformed bracts; on Quercus prinoides. Figures 305, 306, 335. 

RANGE. — Probably as given for the agamic form prinoides (fig. 62) ; probably restricted to an area on or near the Atlantic Coastal Plain. This bisexual form known only from: Massachusetts: eastern part (M. T. Thompson coll. No. 166). Connecticut: Waterbury (types, Bassett). New Jersey: Lakehurst (acc. Beutenmuller 1911). 

Altho not represented by many collections, the good-sized series of this insect in the Bassett and Thompson collections indicate that proper search should reveal this as a very com- mon even if obscure form in the leaf and flower buds of the chinquapin oak, Q. prinoides. Bassett described the galls as fully developed when the staminate flowers of the oak are in bloom. He remarked that “When the gall happens to be in a leaf bud, it is often found at the summit of a young branch one or two inches long, so rapid is the growth of the tree at this season. . . . The insects appear in both sexes about the middle of May ...” [at Waterbury, Connecticut] . A Bassett specimen in the American Museum is labelled as in coitu on May 10 (1879) . Thompson found the galls late in May in eastern Massachusetts, and Beutenmuller recorded (in Smith 1910 :599) galls occurring in May and June— the cells probably being empty for some time before they disappear from the dried-up flower buds. 

Bassett originally spelled this name gemula, a feminine adjective meaning moaning or complaining. It seems evident that Bassett intended to write gemmula, a noun meaning a small bud. This would aptly describe the gall of this insect. Perhaps it is not certain that Article 19 of the International Rules allows an emendation of this original form as a lapsus calami; but perhaps we need common sense rather than rules in this case. Gemmula is here taken to be the bisexual form alternating with the agamic prinoides. My reasons for this opinion are as follows : 

The insect shows the generic characters of a bisexual Cynips as established by the life histories experimentally determined for varieties of folii and divisa, and for erinacei. The insect belongs to the subgenus Acraspis, as evidenced by the character of the hypopygial spine, the wing-body ratio, and the blotches (even tho obscure) in the cubital cell. 

The relation to an agamic Acraspis is further proved by the close resemblance of gemmuia to bicolens, the experimentally demonstrated bisexual form of Cynips pezornachoides erinacei. 

That gemmuia is not also a form of pezornachoides is shown by the host on which it occurs, namely Quercus prinoides, one of the chestnut oaks. Pezornachoides occurs only on the true white oaks of the Q. alba group, and is rigidly excluded from the chestnut oaks. 

Cynips hirta and prinoides are the only agamic forms of Acraspis known from the chestnut oaks, and prinoides is the only Acraspis known from Quercus prinoides. 

Prinoides , then, seems to be the only agamic Cynips of which gemmuia might be the alternate, and none of the data are in conflict with the conclusion that these two are really alternates. 

Acraspis gemula Bass.
var. gemula Bass.
Bi-sexual form, gemula Bass.

Gall, egg-shaped, in buds or surrounded by deformed bracts.

Adults, May.

On Q prinoides.

Cynips fulvicollis Fitch
Bi-sexual form, pallipes bass.

Gall, egg-shaped, inside buds or deformed or dwarfed leaf clusters.

Adults, April, May.

On Q alba, michauxii

Plant Galls and Gall Makers

Acraspis gemula

Quercus alba, bicolor, macrocarpa, prinoides, prinus [montana]
Bud galls
Oval, black, at apex of new growth, 2.5 by 1.25 mm, in May.

"Like Acraspis gemula"

Quercus margaretta, michauxii, stellata
Bud galls

[Photo caption]
On Q alba. Also on Q prinoides, prinus [montana], bicolor, macrocarpa, margaretta. Adults emerged Apr 2-3 1945; May 5, 1935, Apr 27, 1927 (DC); Apr 20-25 (IL).

Philonix pallipes

Quercus alba
Bud galls
Black, at apex of new growth, like gemula in shape, surrounded by thread-like bodies. May. Included from lit.

[Photo caption]
Q alba. Similar to Fig 108 [Acraspis gemula] but with thread-like bodies about its base, blackish-brown, 2.25 mm long. Adults in May.

Acrapis gemula, syn. nov.

Philonix pallipes

Comments. Kinsey (1930) transferred Dryophanta pallipes Bassett into Philonix and considered it as the sexual generation of P. fulvicollis. However, Kinsey provided no justification for  this  synonymy [Kinsey seems to have assigned pallipes to fulvicollis based on a process of elimination]. Weld (1959) wrote that P.  pallipes  was  perhaps  a  synonym  of  Acraspis gemula (Bassett)î. We compared the three specimens of P. pallipes (from Beutenmueller collection, USNM, Washington, DC) with the paratypes of the sexual generation of A. gemula and found no differences. Philonix pallipes is a syn. nov. of A. gemula. If P. pallipes (Bass.) is treated as  an  Acraspis species, there is no evidence that species of Philonix have alternate  sexual generations.

Review of the world genera of oak cynipid wasps (Hymenoptera: Cynipidae: Cynipini)

Philonix fulvicollis Fitch, 1859(1858), sexual generation

Comments. Kinsey (1930) transferred Dryophanta pallipes Bassett, 1900 to Philonix and proposed it as the sexual generation of P. fulvicollis, although no justification for this synonymy was provided. Weld (1959) wrote that P. pallipes might be well a synonym of Acraspis gemula. Melika & Abrahamson (2002) compared the three specimens of P. pallipes (from Beutenmueller collection, USNM, Washington, DC) with the paratypes of the sexual generation of A. gemula and found no differences, thus Philonix pallipes was synonymized with A. gemula. 

Pairing of sexual and asexual generations of Nearctic oak gallwasps, with new synonyms and new species names (Hymenoptera: Cynipidae, Cynipini)

It seems likely that Melika's synonymy of Acraspis gemula and Philonix pallipes is either incorrect, partial, or the original gall descriptions are somehow incomplete. Philonix and Acraspis sexual generation galls of many species are likely collected in this current name. It isn't clear whether Kinsey's varieties and species will end up matching those that are ultimately determined by rearing experiments. 

According to Scott Digweed (personal communication): "A helpful diagnostic character for Acraspis and Philonix (and Disholcaspis, for that matter) sexual galls on bur oak is that Acraspis are tan (and associated with bud scales), Philonix are chocolate brown, and Disholcaspis are creamy or pinkish."


Gallformers ID Notes