Sex. gen. of Neuroterus batatus (Fitch)

Stem galls.
OAK POTATO GALL. Irregularly fusiform, tuber-like stem swellings, 10-40 mm. long by 15 mm. in diameter, deforming the terminal twigs of small trees or sprouts of Q. alba.
In spring at base of the new growth, fleshy, green, glaucous, the adults emerging the latter half of June.

Neuroterus quercus-batatus (Fitch)

Quercus alba
Stem galls, woody stem swellings
Sex. gen. Green, covered with pale blue bloom, 15 mm. in dia., on new growth in June.

[Photo caption]
Fig 125. On Q. alba. Photo also shows the alternating sex. gen. covered with bluish bloom. Adults emerge June 16-25 (IL), May 21 (DC).

[Presumed synonyms]
Quercus breviloba
Stem galls, woody stem swellings
A stem swelling 10 by 30 mm like the summer form of Neuroterus quercus-batatus

Neuroterus quercusbatatus (Fitch)

Cynips Quercus-batatus Fitch 1859: 810. Females and males (type examined).
Neuroterus batata Basset: Ashmead 1885a: 296, 303.
Neuroterus batatus form bisexualis Kinsey 1920: 334.
Neuroterus (Dolichostrophus) batatus var. batatus form bisexualis Kinsey 1923: 4.
Neuroterus quercusbatatus: Burks 1979: 1074.
Cynips noxiosus Bassett 1881: 108. Females, males, galls of both generations (types examined). New synonymy.
Neuroterus noxiosus form vernalis Kinsey 1920: 337. Bisexual generation.

Distribution.-Ontario, Rhode Island, Connecticut west to Illinois, Colorado, south to Florida.

Biology.-Alternate bisexual and unisexual generations are known. Both generations induce stem-swelling galls on Quercus alba L. (Ashmead 1885a, Burks 1979). In Florida, the galls of the bisexual generation also develop on Q. chapmanii and Q. margaretta. The gall is a woody, elongate stem swelling. It is polythalamous, with an irregular shape and a surface that is covered by normal bark, twisted, but in large part cylindrical, tapering gradually to the stem at both ends and up to 20 mm long and 8 mm wide in the bisexual form. Sometimes several galls can more or less fuse, drying brown in bisexual forms, or with a whitish or purplish bloom in unisexual forms [an apparent mistake, copied from Kinsey; these should the other way around]. Internally hard and woody, the tissue is little modified except by the larval cells which are densely packed, each with a distinct but wholly inseparable lining. The bisexual form is on older stems involving the bases of the petioles. The galls of the bisexual generation are less woody, usually on younger twigs, and develop in late spring to early summer. The adults emerge in June and July.

C. q. batatus Fitch.

Quercus alba.

I am satisfied that there are annually two generations of C. q. batatus. The first appears early in May, from galls of the preceding year's growth,--the last late in June, from green galls. I have often found perfect insects in the galls in winter, and have reared flies from them, apparently of the same species reared from the summer galls. Inquilinae in great numbers are produced from the winter galls and few true gall flies, while the reverse is true of the summer form. As many of the summer galls remain green after the flies have left them, and as the tree's annual growth is nearly or quite complete the first of July, it seems probable the June flies oviposit in the galls from which they were produced.

Neuroterus batatus (Fig. 8), pale bluish bloom, corky, many larval cells

Neuroterus batatus (Fitch)

The succulent stem galls of the sexual generation on the new growth were seen [in IL and IN] the adults emerging at Evanston June 16-25, 1913, at Michigan City June 26, 1906.

Oak-potato Gall-fly, Cynips Quercus-batatus, new species.

A large, hard, uneven swelling, three-fourths of an inch thick and twice or thrice as long, resembling a potato in its shape, growing on white oak twigs more distant from their ends than the Oak-tumor.

This gall might be mistaken for a large example of the Elliptic variety of the one first described ["Cynips quercus-arbos"--Callirhytis clavula?], but at each end the swelling arises much more abruptly from the limb, and on all sides of it, whereby the limb is wholly obliterated. Its surface is coated with a glaucous pale blue bloom. Internally it is of a dense corky texture in which are hard woody spots.

Neuroterus batatus form bisexualis, new name

Galls. — Moderate-sized swellings (Figs. 8 and 9) of young stems and petioles, essentially the same as the galls of the agamic generation (q. v.), but differing in being often much smaller, often having tufts of short, woolly pubescence. On stems, petioles, or midveins of Quercus alba.

Range: Canada. NH, MA, RI, CT, NY, NJ, VA, OH, IL, MI, CO

In 1864 Bassett reported that he had observed for a number of years the alternation of two crops of galls on a small tree near his house. The abundance of each crop in turn suggested the relationships of the two. Moreover, the insects proved indistinguishable except through a slight difference in size and in the then unexpected condition of having- only females in the winter galls, with both males and females in about equal numbers from the spring galls. Neither Bassett nor later workers have actually seen the oviposition of the species, nor obtained under con- trolled conditions the gall of one generation from an egg deposited by a female of the previous generation, but Bassett’s field experience is regularly confirmed by later collectors of gall- wasps. I have examined material from the Bassett collection which shows this, also photographs of material collected by Miss Cora Clarke, and a quantity of material collected and bred by Millett T. Thompson. This latter material shows the two generations often close together on successive parts of the same branch. The descriptions here given are made from a study of many specimens which I have compared with the Bassett types. No previous separation has been made of descriptions of the two forms of adults, and the gall of the bisexual generation has never been described in detail, nor have Latin names been applied to distinguish the forms.

The galls of the bisexual generations appear about the middle of May and the adults emerge, in about equal numbers of the sexes, by the middle of June. These oviposit in the new wood of the stem on which the better-known gall of the agamic generation develops.

Neuroterus batatus Fitch
Bi-sexual form, bisexualis Kins

Gall, moderate sized swellings of young stems and petioles.

Adults, June

On Q alba

Neuroterus batatus var prini Kins
Bi-sexual form, prini Kins

Gall similar to that of noxiosus form vernalis on Q prinus [montana]

Adults, June, July

Neuroterus (Dolichostrophus) batatus (Fitch)

GALL.--A woody, elongate stem swelling, wholly inseparable. Polythalamous, with a great many larval cells. Of irregular surface and shape, twisted, but in large part cylindrical, tapering gradually to the stem at either end; up to 20 mm in length and 8 mm wide (bisexual forms); but sometimes several galls more or less fused, the surface covered with normal bark, drying brown in bisexual forms, with a whitish or purplish bloom in the agamic forms [this is backwards compared to every other source except Melika et al 1997, who clearly copied their description from Kinsey]. Internally hard and woody, the tissue not considerably modified except by the larval cells, these cells densely packed, largely toward the surface, each with a distinct but wholly inseparable lining. The bisexual form on older stems involving the bases of the petioles; on white oaks.

Neuroterus batatus variety batatus
bisexual form bisexualis Kinsey

Involved, without distinctive name, in most references to the agamic form dated 1865 or later.

Gall. — Similar to that of the agamic generation, but much smaller. On young stems of Quercus alba. These galls start growth about the middle of May, the adults emerging, in about equal numbers of the sexes, by the middle of June or later.

Neuroterus batatus variety prini, new variety
bisexual form prini, new form

Neuroterus noxiosus
Neuroterus noxiosus form vernalis

Gall.--Similar to that of noxiosus form vernalis; on Quercus prinus [montana].

Range.--RI or eastern MA. Probably confined to Q prinus [montana] in a more northeastern part of the US.

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 quercusbatatus (Fitch 1959)

Hosts: Quercus chapmanii

[Sexual generation stem swelling gall found in Florida in the spring.]