Neuroterus quercusbatatus (agamic)

Neuroterus vesicula (sexgen)

Neuroterus affinis (sexgen)

Neuroterus contortus (agamic)

Neuroterus perminimus (sexgen)

Neuroterus bassettii (sexgen)

Neuroterus quercusbatatus (sexgen)

Neuroterus quercusbatatus (sexgen) (q-bicolor)

Neuroterus quercusbatatus (agamic) (q-bicolor)

Neuroterus bussae (sexgen)

Neuroterus niger (agamic)

Neuroterus papillosus (sexgen)

Neuroterus saltatorius (agamic) (saltatorius)

Neuroterus saltatorius (sexgen)

Neuroterus washingtonensis (sexgen)

Neuroterus pallidus (sexgen)

Neuroterus quercicola (pacificus) (agamic)

Neuroterus howertoni (agamic)

Neuroterus engelmanni (agamic)

Neuroterus cockerelli (agamic)

Neuroterus floricola (sexgen)

Neuroterus saltatorius (australis) (agamic)

Neuroterus saltatorius (decrescens) (agamic)

Neuroterus saltatorius (texanus) (agamic)

Neuroterus umbilicatus (agamic)

Neuroterus distortus (sexgen)

Neuroterus evanescens (sexgen)

Neuroterus exiguus (sexgen)

Neuroterus tectus (sexgen)

Neuroterus niger (sexgen)

Neuroterus quercusminutissimus (agamic)

Neuroterus quercusverrucarum (agamic)

Neuroterus clarkeae (sexgen)

Neuroterus dubius (sexgen)

Neuroterus quercusirregularis (sexgen)

Neuroterus minutus (sexgen)

Neuroterus congregatus (sexgen)

Neuroterus quercicola (agamic)

Neuroterus fragilis (sexgen)

Neuroterus quercicola (pacificus) (sexgen) (q-douglasii)

Neuroterus quercicola (pacificus) (sexgen) (q-lobata)

Neuroterus varians (agamic)

Neuroterus rileyi (agamic)

Neuroterus virgens (agamic)

Neuroterus vesicula (cerinus) (sexgen)

Neuroterus floccosus (agamic)

Neuroterus pattersoni (sexgen)

Neuroterus contortus (sexgen)

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 60 mm long by 20 mm wide (agamic 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 agamic form on young stems, involving petioles and leaf midveins; on white oaks. 

Neuroterus batatus variety batatus 
agamic form batatus (Fitch)

Cynips Quercus-batatus
Cynips quercus tuber
Cynips batatus
Neuroterus batata
Neuroterus batatus
Neuroterus quercus-batatus

Gall.--As described for the species; large, woody, on stems of Quercus alba.

Range.--NH, MA, RI, CT, NY, NJ, New Brunswick. Probably restricted to a northeastern area of the US.

The gall of this generation begins development in midsummer, the insects remaining in the galls over winter and emerging in April or early in May. Thus this agamic generation takes nine or ten months to develop, while the bisexual occupies only a couple of months. This variety is probably restricted to the single oak, Q, alba, in the northeastern part of the United States. The insect of variety noxiosus is very similar, differing mainly in coloring and its restriction to Q, bicolor. 

Neuroterus batatus variety obtusilobae (Karsch)
agamic form

Diplolepis (Neuroterus) q. obtusilobae
Cynips obtusilobae
Neuroterus obtusilobae
Neuroterus quercus-obtusilobae

Gall.--As described for the species; on Quercus stellata.

Range.-- TX. Probably confined to more eastern TX and parts of adjacent states.

Neuroterus batatus variety prini
agamic form deprini, new form

Neuroterus noxiosus form noxiosus

Gall.--As described for the species for agamic forms; on Quercus prinus [montana]

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

Neuroterus vesicula

Gall.--A small, thin-shelled, globular bud or bark gall. Monothalamous, up to 3 mm in dia; rather thin-walled, quite globular, the bud galls succulent and shrivelling on drying; the bud galls colored light green and drying light or dark brown; internally entirely hollow, without a distinct larval cell. In a terminal or lateral bud, partly covered by normal bud scales; on white oaks and chestnut oaks.

Range.--MA to MI and TX. Probably throughout the eastern half of NA wherever white oaks occur.

Varieties:

Neuroterus vesicula variety affinis
[Bud gall on Q prinoides]

Neuroterus vesicula variety ocularis
[Bud gall on Q stellata]

Neuroterus vesicula variety vesicula
[Bud gall on Q alba]

Neuroterus vesicula variety affinis

Cynips affinis
Neuroterus affinis
Neuroterus vesiculus

Gall.--As described for the species: [A small, thin-shelled, globular bud gall. Monothalamous, up to 3 mm in dia; rather thin-walled, quite globular, the bud galls succulent and shrivelling on drying; almost smooth, but microscopically pebbled; the bud galls colored light green and drying light or dark brown; internally entirely hollow, without a distinct larval cell. In a terminal or lateral bud, partly covered by normal bud scales.]

Range.--CT Probably confined to a northeastern area of the US

Bassett stated that these galls start growth in the autumn and mature early in the spring, the insects emerging by the time the leaves begin to expand. The variety is undoubtedly confined to Quercus prinoides, a distinct oak which always has a unique cynipid fauna. There are so many well-defined differences between vesicula and affinis that it would be a great loss to consider the two as synonyms. Bassett saw that the two insects are related but distinct, and it is a step backward to ignore such non-identities.


Neuroterus contortus 

GALL. — An irregular stem swelling, wholly inseparable. Polythalamous. Individual galls up to 20. mm. long and 8. mm. wide, but sometimes several galls are closely adjacent and more or less fused. Externally very rough, small, irregular, raised spots indicating some of the larval cells; covered with greenish, young bark, drying browner. Internally woody, most woody centrally, with a great many, densely packed, small larval cells, 1.7 mm. long by 0.7 mm. in width, mostly toward the surface; the lining distinct but wholly inseparable. On young stems, involving young petioles and deforming the young leaves; at the crowns (or on roots?) of Quercus breviloba (figs. 58, 59). 

RANGE. — Texas: Austin. Probably occurs thruout eastern Texas and adjacent parts of Louisiana and Oklahoma. The agamic generation is known from galls and adults obtained by Weld in 1917, and from a quantity of material Dr. J. T. Patterson has bred. Several hundred insects of the bisexual generation were bred by Dr. Patterson in the spring of 1922. I first connected the alternate generations of this insect on the basis of the complementary dates of development and the extremely close similarity of the insects and galls, and this similarity is enough to make the relation unquestionable. Dr. Patterson confirms this by his experimental data. 

The agamic generation starts growth in April; Dr. Patterson describes the galls as nearly fully formed by the last of April, with small larvae in the galls by July; Weld found pupae on October 16 and 30, with live adults in the galls on December 1 and 12. Emergence is in the relatively mild winter season of Texas or in the early spring, from before the last of January to after the 7th of February, according to Dr. Patterson’s records. Dr. Patterson states that he has secured 10 males with 231 females of this agamic generation, but that these males are unable to mate with the females, altho they attempt to copulate; the females appear to have completely lost the mating instincts, as have the males to some degree. These males are apparently functionless, which is a most interesting case of this sex persisting as a generation becomes agamic. I have seen four of these males. The bisexual generation develops quickly in the spring. Dr. Patterson obtaining adults on April 3, 1922. He has sent me almost three times as many males as females, so probably the sexes occur in about equal numbers. The galls of the two generations are similarly located at the crown of the tree, and differ very little in structure. I do not see any differences between the insects of the two except in the larger size which is almost always correlated with agamic reproduction of Cynipidae. The close similarity of the alternates is one reason for placing contortus in this genus. This is the only root gall yet known in Neuroterus, but the gall is sometimes on stems at the crown of the tree. Weld records a specimen of this species obtained from Palestine, Texas, on Quercus stellata. It may belong to a distinct host variety. Probably still other white oaks of eastern Texas, Louisiana, and Oklahoma are hosts for this species. 

Neuroterus contortus agamic form contortus 

GALL. — Not greatly different from the gall of the other generation, somewhat larger and more smooth, probably due to the leaves having worn off (fig. 59).

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. 

Neuroterus vernus variety bassettii bisexual form

Neuroterus pallipes
Neuroterus bassettii
Neuroterus pallidipes

Gall.--Small, slight, one-celled swellings, usually covered with a rather thick, ragged pubesence; on petioles and veins, dwarfing the leaves of Q alba.

Range.--MA, NY, NJ

This insect comes very close to being a synonym of exiguus, the slightly larger areolet and the host being the only good characters for distinguishing bassettii. I have seen a paratype female, and males from the type locality, host, and collector. This American Museum material is dated June 2; Beutenmuller says the galls are to be found in May. Probably other tissues are affected, and other forms of galls produced, as well as those now described. The name pallipes which Bassett first applied to this insect is preoccupied by Neuroterus pallipes Schenck, 1862, and Dalla Torre substituted the name bassettii for our insect. In doing so he referred to the Bassett insect as pallidipes, by mistake. It is true that the Schenck insect is not a Neuroterus, but as long as pallipes had ever been previously published in combination with Neuroterus, that name is unavailable for any other insect. Beutenmuller and subsequent authors are in error in considering pallipes still available for Bassett’s insect. 

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.

Neuroterus batatus variety noxiosus
bisexual form vernalis Kinsey 

Involved, without distinctive name, in most references to the agamic form. 
Neuroterus noxiosus form vernalis

Gall.--As described for the species; twisted, moderately woody, on young stems, petioles, and leaf-midveins of Quercus bicolor. This gall starts growth in May, the insects emerging from June 12 to July 5.

Range.--MA, RI, CT, NY, NJ, New Brunswick

Neuroterus batatus variety noxiosus 
agamic form noxiosus (Bassett) 

Cynips noxiosa
Neuroterus noxiosus
Neuroterus noxiosa
Neuroterus consimilis [see ID Notes]
Neuroterus noxiosus form noxiosus

Gall.--As described for the species; large, woody, on stems of Quercus bicolor. This agamic gall begins to develop in mid-summer, the insects staying in the galls nine or ten months, emerging from March 24 to early May. Noxiosus has always heretofore been considered a distinct species, no one having pointed out the very close resemblance to batatus. If this is remembered it will help one to understand the distinctness of my other varieties. Noxiosus differs from batatus mainly in slight color characters, the slightly different shape of the abdomen, and the size of the areolet being the total of other differences. To be consistent, some workers should treat noxiosus as a complete synonym of batatus, which no one will do in the face of the patent loss of good host and life history data. 

Range.--MA, RI, CT, NY, NJ, New Brunswick

Neuroterus niger variety alimas, new variety 
bisexual form 

GALL. — Rather slender, elongate, distinctly bounded on the upper surfaces; without a trace of a central point; often two cells somewhat fused; on Quercus virginiana. 

RANGE. — Texas: Austin (Patterson coll.); Leander. Probably confined to a region in central Texas.

A rather similar gall, Neuroterus howertoni, occurs on the same leaves with alimas, but howertoni galls have a hollow, cone-shaped eruption on the under surfaces of the leaves; the insects of the two are less distinct than their galls.

Neuroterus niger variety niger Gillette 
agamic form 

Neuroterus nigrum
Neuroterus niger

GALL. — Rather rounded, somewhat elongate, with well-defined boundaries, without a central point on the upper surface. On Quercus macrocarpa. 

RANGE. — Iowa: Ames (Gillette). Illinois: Algonquin (Nason). Michigan: Lansing (Gillette). Possibly confined to a smaller area about Ames, Iowa. 

Gillette stated that the galls of this agamic generation appear late in August; he collected his galls on October 20, 1887 ; adults emerged on May 10, 1888. The Thompson material also over-wintered in the galls, emerging about the middle of May. Beutenmuller’s further data appear to be derived in part from variety perminimus which he considered a synonym of niger.

[Neuroterus niger variety arizonicae](https://www.biodiversitylibrary.org/page/53512324#page/299/mode/1up), new variety 
agamic form 

GALL. — Rather circular, slightly elongate, with only an indefinite trace of a point on the upper surface; the boundaries very indefinite, especially on the under surface; on Quercus arizonica. 

RANGE. — Arizona: Bisbee, Fort Huachuca, Whetstone, Salford, Globe, Santa Catalina Mountains (Sabino Trail). New Mexico; Alamogordo. Probably thru Arizona, New Mexico, and adjacent Mexico, wherever Q. arizonica occurs. 

The insects probably do not emerge until late in January or February.

[Neuroterus niger variety griseae](https://www.biodiversitylibrary.org/page/53512324#page/300/mode/1up), new variety 
agamic form 

GALL. — A little more elongate than circular, with very poorly defined boundaries and not much thickening of the blade, perceptible mostly because of a discoloration, less perceptible on the under surface. On Quercus grisea. 

RANGE. — Texas: Fort Davis. New Mexico: Hillsboro. Probably occurs in West Texas, New Mexico, and adjacent Mexico (and Arizona?).

The insects probably did not emerge from the galls until early in the spring after collecting. The galls are indistinct and not at all noticeable; the insect is clearly different from other varieties; so it seems worth describing even tho the type material is not abundant. 

[Neuroterus niger variety nigripes](https://www.biodiversitylibrary.org/page/53512324#page/301/mode/1up), new variety
agamic form

GALL. — About circular, slightly elongate, very slightly larger than pattersoni, with less well-defined boundaries and with a distinct central point on the upper surface. On Quercus stellata and Q. breviloba (fig. 34, 42).

RANGE. — Texas: Austin, Leander.

Larvae were in the galls I collected on December 4, 1919. Dr. Patterson has made detailed observations on this species, finding that the young galls were evident on July 28, 1921, Indiana University Studies maturing-about the first of December ; he secured adults about the first of March, 1921. Dr. Patterson has bred galls from both Q. stellata and Q. breviloba, and I cannot see any differences between the two lots of material. Another variety, pattersoni, also occurs at Austin on both of these oaks, but the insects and galls are always distinguishable. Evidently two faunal areas, meeting at Austin, have effected an isolation which is not accomplished by the two hosts.

[Neuroterus niger variety pattersoni](https://www.biodiversitylibrary.org/page/53512324#page/303/mode/1up)
agamic form hiemalis, new form

GALL. — Probably quite similar to that of the bisexual generation. On Quercus breviloba.

RANGE. — Texas: Austin (Patterson coll.).

The occurrence on the two different hosts is not remarkable; probably both forms occur on both stellata and breviloba at Austin. This is true of variety nigripes, and care must be taken to distinguish pattersoni and nigripes; the characteristics in the descriptions are quite constant guides to both insects and galls.

Neuroterus niger variety papillosus Beutenmuller 
bisexual form 

Neuroterus papillosus
Neuroterus papillatus Beutenmuller

GALL. — Elongate, quite slender, small, with fairly well-defined boundaries, without a trace of a central point on either side. On Quercus bicolor (fig. 35). 

RANGE. — Rhode Island: Providence (in Thompson coll.). New York: Bronx Park, New York City (Beutenmuller) ; West Nyack (Felt in N.Y. State Mus.). Probably confined to a more northeastern area of the United States, on Q. bicolor. 

I have not been able to examine the types of this variety, and have made my descriptions from Q. bicolor material from West Nyack, New York, sent me by Dr. Felt. I have galls from the Thompson collection, from the typical host, from Providence. These agree with Beutenmuller’s figure in being narrowly elongate, and quite distinct from the more circular galls of niger or perminimus. The cynipid fauna of Q. bicolor is usually unique, and it is not likely that this variety occurs on any other host. 

Neuroterus saltatorius variety saltatorius

GALL. — Quite ellipsoidal, almost half again as long as wide, aciculately roughened, apically with a blunt tip which is slightly hairy; gall rather large; on Quercus lobata (and Q. Douglasii?) (figs. 27, 30, 31). 

RANGE. — California: Marysville (Aaron coll.); Stockton (acc. Calif. Acad. Proc.) ; Brentwood, Stanford University (McCracken) ; Diablo (Leach coll.) ; Sacramento (C. T. Dodds) ; Paso Robles, Exeter, Napa. Probably thruout Central California over the range of Q. lobata (and Q. Douglasii?). 

The variety occurs most commonly on Quercus lobata; a very similar gall, possibly of the same variety, occurs less often on Q. Douglasii, but I have not secured insects and cannot be sure of the relationships. The records for other hosts, as previously pointed out, apply to other varieties. Riley was wrong in considering the eastern United States material identical. Beutenmuller (1910) made the correction, but he did include a figure of a Connecticut, Quercus alba specimen (plate XI, fig. 9). 

It is not clear at what season Aaron collected the type material, but the California Academy had previously seen galls (as Mr. Weld points out to me) which were about mature and dropped to the ground in August. Material in the Stan- ford and University of California collections was collected in August and in September as late as September 24. No one, apparently, has ever secured a male of this species, and I fail to find any males in the material collected in September and sent me from the Stanford collection by Dr. McCracken or in the material sent by Professor Essig and Mr. Dodds of the University of California. This amounts only to negative evidence, and we need further proof that this summer generation is agamic, but it does look as if here might be a case of a species in which no bisexual generation ever does occur. I have further examined fine lots of saltatorius material collected at frequent intervals thru the late fall and winter of two years by Mr. Leach, and these galls do not mature until January or February, the insects emerging late in the winter or early in the spring. This is very evidently the winter generation, agamic as we have observed and as would be expected in Neuroterus. I have not described these two generations as different forms because they are apparently identical (even as to sexuality) except for their seasonal occurrence. 

Neuroterus saltatorius (bisexual generation) / Neuroterus decipiens 

A leaf blade swelling involving both surfaces of the leaf; each larval cell apparent on the surface as a distinct, egg-shaped cell, the walls thin and without any other cell lining, each cell about 1.7 by 1.0 mm.; clusters up to about 15. mm. in diameter contain up to 60 cells; succulent as the young leaf.

Host:
Quercus douglasii (figs. 49, 50)

Neuroterus quercicola variety washingtonensis
bisexual form

A rather large vein swelling involving and deforming more or less of the blade; of indefinite shape; green, succulent when fresh, drying brown and rather hard, without much shrivelling; up to 35. mm. in length and 15. mm. in diameter. On leaves of Quercus garryana.

Range:
OR, WA

Weld's galls, collected on July 2, 1911, gave adults July 30. This is considerably later than the March and April emergence of variety pacificus further south, and shows the considerable dependence of cynipid development upon the development of the host. 

The above descriptions are made from paratypes. The insect differs only slightly from pacificus, but has not gone the way of the usual synonomy. The gall is very much like that of pad ficus on Q. Douglasii. It is possible that the aments of garryana will show galls of variety washingtonensis similar to the ament galls of pacificus on Q. lobata. The alternate generation of this insect may be either a similar leaf swelling, a woody stem swelling, or a cell in an acorn cup, and I have collected the latter gall at Ashland, Oregon.

Neuroterus minutus variety pallidus Bassett 

Neuroterus pallidus

Hosts: Quercus bicolor

GALL. — A compact cluster of seed-like cells in the aments. Each cell usually monothalamous, egg-shaped, about 2.0 mm. long by 1.2 mm. wide, drying brown in color; thin-walled, entirely hollow, without any other wall of a larval cell. Forming compact clusters 7. by 3. mm. ; on the aments of Quercus bicolor (fig. 44). 

RANGE. — Connecticut: Waterbury (Bassett). New York: New York City (Beutenmuller). New Jersey (Beutenmuller). Probably confined to Q. bicolor in a northeastern part of the United States. 

Neuroterus quercicola variety pacificus 
agamic form varians Kinsey

Neuroterus quercus-batatus (woody gall only)
Neuroterus pacificus (woody gall only)
Neuroterus varians
Neuroterus cupulae

GALL. — A slight swelling of the affected part, the larval cells with a distinct but inseparable lining; galls of two types as follows: 

Acorn Galls: Single larval cells buried in the wood of the acorn cup. The cell oval, averaging 1.5 by 2.2 mm.; with moderately thin walls. Buried wholly or in part in the wood of the acorn cup, oftenest at the base; part of the cell sometimes visible within the cup, only rarely producing a slight swelling on the outside (fig. 57). 

There can be no question of the identity of varians and cupulae. I described these as distinct species primarily because the galls of the two are so very different that the possibility of their identity never was entertained. I never compared the two descriptions, and only a revision of the whole genus, analyses of subgenera, and the writing of comparative descriptions, Anally showed me the mistake. This is an indictment of the publication of miscellaneous new species, and justification of the revision of whole groups at a time. Varians and cupulae are synonyms, not because the insects largely resemble each other, but because detailed examination of large series of the types of the two fails to disclose a single point of constant, group difference. Insects were emerging from both kinds of galls at the same date from the same trees at Paso Robles in 1920. 

Here is one of the most remarkable cases known of one cynipid producing two or more distinct kinds of galls on different parts of the host. Several other cases are pointed out in this paper for the genus, but otherwise few cases of gall polymorphism are known in the Cynipidae. Varians lives either in twigs or acorn cups. In the first instance the galls are polythalamous swellings packed with larval cells, while in the second instance they are single, scattered larval cells which produce almost no swelling. So does the plant tissue determine the character of the gall! It might be suggested that the two insects, altho alike morphologically, are different physiologically as evidenced by their different points of oviposition, but such matters cannot be investigated with our present means. Meanwhile it appears probable that insects from either type of agamic gall lay eggs for either type of bisexual gall, apparently due to the lack of a peculiar physiology which might restrict oviposition to a single point on the plant. 

Range: CA, thruout central CA and possibly wherever Quercus douglasii and lobata occur.

Neuroterus (Diplobius) howertoni, agamic form

Neuroterus howertoni

Gall. A small, eruptive swelling on the under surface of the leaf blade. Each “monothalamous’’, up to 1.5 mm. in diameter. The larval cell closely imbedded in the leaf, without a distinct wall, the gall evident on the upper surface only by a very slight, papilla-like swelling, colored more yellowish or brown than the leaf blade; on the under surface forming a more distinct, cone-shaped swelling with a central depression, resembling a “volcano” cone; more often leaf color on the under surface, and not pubescent except with the microscopic pubescence normal to the leaf. In numbers on each leaf, on Quercus virginiana and other live oaks (figs. 37, 38). 

RANGE. — New Mexico (Bassett). Texas: Austin, Leander, Skidmore, Hondo. Possibly distinct varieties occur in the two states. 

This is practically a physiologic species, for the insect is not satisfactorily distinct from niger or verrucarum, differing in a few characters which appear only of varietal impor- tance in this portion of the genus. The galls, altho quite suggestive of niger are so distinct that they ought to be considered a separate species, especially since the same oaks over the same region bear typical niger galls. In a similar situation with Neuroterus verrucarum pulvinus I gave only varietal rank to the physiologic group, but we as yet have so little insect material of howertoni that I do not feel warranted in too definite an opinion as to relationships. 

Bassett’s type material was from an undetermined oak, which it would now appear was Q. grisea. The distinct host, Q. virginiana, from which my material came, may isolate a distinct variety, and the two faunal areas involved may further effect isolation, but altho I have insects from all three of the Texas localities, they are not sufficient for varietal studies. My galls contained larvae in the first half of December and gave adults at some later date, probably in early spring. Dr. Patterson has cut adults from galls in the last of December. As Bassett stated, the insects emerge from the lower surfaces of the galls, but the normal, central depression should not be mistaken for an exit hole. 

Neuroterus niger variety engelmanni, agamic form

Hosts: Quercus engelmanni

GALL. — About circular, with rather well-defined boundaries, often with an indefinite central point on the upper surface. On Quercus engelmannii (fig. 39).

RANGE. — California; Alpine, Fallbrook. Probably confined to the limited range of Quercus Engelmannii, in southern California and adjacent Mexico. 

Neuroterus cockerelli

Hosts: Quercus sp

GALL. — On the leaves of a species of oak. Hemispherical or subhemispherical, pale brown, minutely crackled, hard and flattened at the base. Width, 4 mm.; height, 2.50 mm. (fig. 36). 

HABITAT.— Manitou, Colorado (T. D. A. Cockerell). 

I have been unable to secure any certain information as to this name. The type may be in the Beutenmuller collection, and is unavailable to me. This is the only published name in the American groups of the genus which I have not been able to interpret. From the original description one might place the insect in Diplobius, and it may be a variety of saltatorius. Professor Cockerell has sent me what appeared to be galls similar to the material he had sent Beutenmuller; these galls were on Q. Gambelii; they fitted the original description and figure, but they contained insects related to Dryophanta eburnea Bassett. The original description of the insect does apply to a Neuroterus, but the possibility of the insect having been wrongly connected with the gall must be considered when some student of Cynipidae has an opportunity to study the Beutenmuller type. In the statistics given thruout this paper, I have treated cockerelli as some variety, instead of a distinct species. 

Neuroterus (Diplobius) floricola bisexual form

Hosts: Quercus douglasii

GALL. — A small, egg-shaped capsule in the ament. Monothalamous, rarely two or three more or less fused. A modified anther, each capsule egg-shaped, almost smooth, microscopically coriaceous, drying brownish yellow, averaging 1.5 by 0.7 mm.; thin-walled, entirely hollow. Scattered in the aments of Quercus Douglasii (fig. 23). 

RANGE. — California: Three Rivers. Probably occurs thruout the range of Quercus Douglasii. 

This gall appears very early in the spring, the adults probably emerging a short time after the buds open on the oak. The species probably has an alternate, agamic generation. It is so closely related to the other species of the sub- genus Diplobius that, as with them, the alternate should be a leaf vein or petiole swelling. As pointed out in the introduction to this paper, the monothalamous, precisely formed anther gall is not as specialized as it looks, but is the inevitable result of a simple proliferation of anther material. 

Neuroterus saltatorius variety australis, new variety

GALL. — Rather spherical, slightly elongate, without an apical tip; entirely but very finely pubescent; rather small; on Quercus stellata.

RANGE. — Texas: Austin (Patterson collector). 

The insects emerged from March 6 to 13, 1923. This gall has been known for some time, but the insect is not easily reared. Dr. Patterson secured only 11 females from many thousands of the galls, parasites being reared however in considerable numbers. This is probably a winter generation, but the summer generation may also be agamic, in a very similar gall. A variety of saltatorius also occurs on Q. stellata in the Middle West and thruout the Atlantic States, but australis is very probably confined to a limited southern area west of the Mississippi. Until we get more locality records I cannot suggest whether this area is in Central Texas or in more Eastern Texas and the adjacent states. 

Neuroterus saltatorius variety decrescens, new variety

GALL. — Elongate, twice as long as wide, up to 0.7 mm. in length; the surface microscopically roughened, irregularly set with a short pubescence; brownish or tinged purplish red; on Quercus arizonica (fig. 29).

RANGE. — Arizona: Bisbee, Prescott. Probably confined to Q. arizonica in a southwestern portion of the U.S. and adjacent Mexico. 

This insect is closely related to the other varieties of saltatorius, but the galls are so distinct as to suggest that decrescens may belong to a distinct species. Until we can breed more material from all of the pubescent, separable galls of the southwestern evergreen oaks, there will be a question as to their specific relations. This is true for the present insect and for an undescribed species producing a more spherical, more pubescent gall on Q. grisea in West Texas. Decrescens is one of the three or four smallest Cynipidae known. 

Neuroterus saltatorius variety texanus, new variety

GALL. — About globose, hardly any longer than high or wide, entirely irregularly roughened, without a trace of a distinct tip apically; gall small; on Quercus virginiana (fig. 28). 

RANGE. — Texas: Austin (Patterson coll.); Yoakum, Skidmore, Hondo, (Leander?). 

I have galls of this variety from several localities, but Dr. Patterson has succeeded in breeding the wasp. He states that the galls appear late in the fall, the insects emerging by March 8 in 1922. My Leander record may apply to a distinct variety confined to a small area in Central Texas. 



Neuroterus umbilicatus agamic form

GALL. — Small, separable, saucer-shaped. Each cell monothalamous. Up to 1.0 mm. in diameter, strictly circular, flattened, centrally depressed, with a low rim, a minute point in the center of the depression; light green, becoming brown; rather densely covered with short hairs; attached by rather a broad point, but quite easily separable, hardly at all imbedded in the blade, but indicated on the upper surface of the leaf by a slight papilla surrounded by a considerable circle of discoloration. Internally entirely hollow, without a distinct larval cell. On the under surfaces of white oaks, commonly on Quercus bicolor (the type variety), recorded from Q. michauxii (acc. Felt), Q. macrocarpa (acc. Jarvis), and Q. stellata (Patterson coll.). Figs. 40, 41. 

RANGE. — Ontario (Jarvis). Massachusetts: Boston (in Clarke coll.); Forest Hills (Kinsey coll). Connecticut: Waterbury (Bassett); New Haven (Viereck). New York: New York City, Staten Island (Beutenmuller) ; Barrytown (Bassett in coll. Mus. Comp. Zool.); Hudson Falls, Mt. Kisco, Sea Cliff (Felt). New Jersey: Ft. Lee (Beutenmuller); Broadway (Kinsey coll.). Pennsylvania, Illinois (Beutenmuller). Mississippi: Pickens (Felt). Texas: Austin (Patterson coll.) . Probably thruout the eastern half of the United States. 

The gall of this species is very common, and a familiar object to all who have hunted galls in the northeastern part of the United States, but the insect is so difficult to rear that, as far as I know, no one has yet accomplished it. Bassett’s type material was obtained by cutting mature adults from galls and by capturing them as they were flying about the oak trees to oviposit. The galls of this agamic form are found on the leaves in late summer, but do not mature until very late in the fall as the leaves are falling. Most of the galls have by then become detached from the leaves, and are soon lost on the ground. By sifting the soil, sand, and leaf-mold, Bassett succeeded in the spring in obtaining galls which contained living wasps. The growth of the insect is probably very dependent upon moisture and temperature conditions of the sort found on the ground thruout the winter months, and the minute galls, with their thin walls, dry out very soon after collecting, explaining the difficulties in breeding the insect. Bassett found insects of this species in numbers over an oak, on a warm spring day, ovipositing in the buds of the tree. He further states that ‘In the latter part of May and the beginning of June the young galls were nearly full grown and as abundant as ever before.” This last must apply to a spring generation, for the galls of the agamic form are not mature until September or later; and inasmuch as Bassett failed to differentiate the spring galls it would appear they are similar to the agamic galls, similarly placed on the leaf. The insect of the spring form may be agamic (as with the closely related saltatorius), or bisexual as with other species of Diplobius, and it will be interesting to determine this definitely. These data have been published for twenty-three years, but have apparently been overlooked as a record of heterogony. 

The type variety is on Quercus bicolor, and the records for other hosts will prove to represent distinct varieties. The type locality is in Connecticut. The Ontario, Illinois, Mississippi, and Texas records will undoubtedly represent as many distinct varieties. The oaks, Q. bicolor, Q. macrocarpa, and Q. stellata, belong to a single group, but Q. michauxii belongs to the group of chestnut oaks. If the last record proves correct, the insect would appear to occur on species of both white and chestnut oaks over all of the eastern half of the United States, with a possibility of upward of 80 varieties. Mr. Frank A. Leach has collected a very similar but slightly different gall on Q. lobata and Q. douglasii from localities in central California; it is possible these will prove varieties of this species, extending its range over the whole of the United States. 

The monothalamous, rather separable gall, connects this species with saltatorius, and the insects of the two are so nearly alike that they can hardly be separated. Here is another case of physiologic species, and a rather remarkable instance inasmuch as the galls of the two are very distinct. When we have discovered a larger number of varieties of each species, we may be able to perceive the specific characters more clearly. 

Neuroterus vernus variety distortus bisexual form

GALL. — A slight swelling of the bud or young leaf, petiole or vein; on Quercus bicolor. 

RANGE. — Connecticut: Waterbury (?). New York, New Jersey (Beutenmuller). Probably confined to a more northeastern part of the United States. 

This insect is closely related to variety tectus, but is apparently due to isolation upon the distinct host. Like tectus, this is a bisexual form, starting growth with the unfolding of the buds and maturing in May or June.

Neuroterus vernus variety evanescens bisexual form

GALL. — A swelling of the ament stem, forming a mass about 5 mm. long; on aments of Quercus breviloba.

RANGE. — Texas: Austin. 

A couple of corrections should be made in the data I originally published with this insect. The types should bear the Patterson number 68 ; the galls appeared about March 19, and the adults began emerging April 4, 1922. Patterson observed the insects ovipositing on the under sides of leaves, and since the variety is so closely related to the varieties which produce leaf vein swellings, there is little doubt that the agamic generation will be found in such a gall. The Patterson material occurring on Q, stellata should be numbered 46. This may represent a distinct variety. 

Neuroterus vernus variety exiguus bisexual form

Neuroterus gillettei

GALL. — As described for the species; swelling on petioles, mid- veins, or ament stems, or anther capsules on Quercus stellata (figs. 24, 25). 

RANGE. — Connecticut: Waterbury (?), West Rock (Bassett). New York (Beutenmuller). New Jersey: Lakehurst (Beutenmuller). Vir- ginia: Rosslyn. Probably confined to a northeastern area of the United States. 

Bassett found his galls in May, the insects emerging by the end of the month. My material from Rosslyn, Virginia, was about ready to emerge on May 16, 1920. 

Felt’s reference to N. floccosus on ament flowers is explained, by Dr. Felt himself, as a clerical confusion of exiguus with exiguissimus and the reduction of exiguissimus to a synonym of floccosus (following Beutenmuller) ; the reference applies to exiguus. 

Gillettei is certainly a complete synonym of exiguus. I have examined good series of paratypes of both names, com- paring them with types of all the related things, and cannot find any differences at all. The hosts of the two are the same. The two type localities are probably near together, altho the locality of gillettei was not definitely given, but in all such cases Bassett appears to have implied Waterbury, Connecticut, and the identity of the types of the two show they came from the same faunal area. The galls of the two names are different, exiguus coming from ament stem swellings (and anther cells), and gillettei from leaf petiole and midvein swellings, and these differences apparently prevented Bassett from seeing the relationship. The two descriptions were published on the same page, but were certainly written at different times, as evidence the great differences in the ordering of material, the choices of terms, etc. The differences in the galls, as for several related species of N euroterus, imply nothing more than that the insects are primitive, can produce only indefinite proliferations, do not restrict their activities to a single part of the host, and consequently are found in galls which vary as different tissues are affected. 

This is further apparent from an experience of mine which closely matches Bassett’s original experience with this insect. He obtained his Netiroterus exiguus types from boxes of galls which gave his Plagiotrichus exiguus (described as an Andricus) . He believed that this latter insect came from tiny, egg- shaped capsules in the aments, and at first he explained the shortened, thickened, compacted condition of the whole ament to the action of the Plagiotrichus. When he found the N eu- roterus in the box he cut open both anther capsule galls and the anther stem swelling. Concerning the anther capsule he states 'T examined the galls very carefully, but found but a single species, and from this the Andricus [Plagiotrichus] surely came, as I found a specimen in the unopened galls.” And later, concerning the stem swelling, he records "After repeated efforts I finally found some of the Neuroteri in these galls and the mystery was solved.” Solved, in part! 

I have large series of both insects from similarly combined clusters of anther capsules and ament stem swellings. My material is from Rosslyn, Virginia, on Q. stellata; I have compared both insects with types and cannot find differences, altho I am not convinced that Rosslyn, Virginia, and Water- bury, Connecticut, are in the same faunal area. At any rate, my material is specifically related to if not varietally identical with the Bassett types. I cut open anther and stem galls to determine the source of each insect. I found, in several instances for each species, both the Plagiotrichus and Neuroterus in both kinds of galls! Here is a case of gall dimorphism to match the several others in the genus, where the gall-producing capacity of the primitive N euroterus is not sufficient to obscure the nature of the plant tissue involved, and where the form of the gall thus varies as different plant tissues are attacked. But in this instance the interpretation is remarkably substantiated when we find two insects of distinct, but in both cases primitive genera, producing quite identical galls when the same part of the plant is attacked. It is possible that no other part of the plant but the ament and particularly the anther would restrict the gall as closely to form. The egg-shaped anther gall is now known from a number of species of Cynipidae of diverse genera (see the discussion of gall polymorphism in the introduction), and there seems to be little chance of the anther ever producing any other type of gall. This comparative, taxonomic study of species is giving us considerable information as to the factors which influence gall production. 

Neuroterus vernus variety tectus bisexual form tectus

Neuroterus tectus

GALL. — A small swelling of closely packed larvel cells, without much other tissue; on petioles, young stems, and flower stems of Quercus prinoides. 

RANGE. — Massachusetts (Thompson). Rhode Island: Providence (Thompson). Connecticut: Waterbury (Bassett). New York, New Jersey, Pennsylvania (Beutenmuller) . 

These galls are inconspicuous swellings, affecting prob- ably any young part of the oak. The insect starts growth with the unfolding of the buds, emerging late in May and early in June in New England; Bassett found galls in part empty by June 10. 

Neuroterus vernus variety tectus agamic form abundans

GALL. — Not certainly identified, but probably a slight swelling of leaf midveins. 

RANGE. — As given for the bisexual generation. 

This insect begins development in midsummer, emerging in the following May. Leaf vein swellings in the Thompson collection may belong to this generation, but the data are not certain. I used the Thompson collections when I named this form, and that should constitute the type material rather than the Bassett material which I named in 1920. Bassett found the agamic females ovipositing, but did not distinguish them from the bisexual form. Millett Thompson also observed agamic insects ovipositing, and from the marked buds ob- tained galls and adults of the alternate generation. The credit of observing this heterogeny should be given to both Bassett and Thompson.

Neuroterus vernus variety vernus bisexual form

GALL. — A slight, irregular swelling of ament stems, young leaf veins, or petioles; on Quercus macrocarpa. 

RANGE. — Iowa: Ames (Gillette). Illinois: Algonquin (Nason). Probably confined to an area in the Middle West. 

Gillette stated that this insect was '‘double brooded’', but failed to distinguish agamic and bisexual forms, not obtaining the male. He noted that the insects of the two generations differ somewhat in color. He stated that the one (agamic) generation emerged in April, the bisexual in May and June. The agamic galls are confined to leaves. I have not seen material, and draw the descriptions from Gillette’s original accounts, 

Neuroterus verrucarum variety minutissimus

GALL. — Similar to the galls of the other varieties; of moderate size, the papilla swelling on the upper surface almost entirely absent (due to the thickness of the evergreen leaf?). On Quercus virginiana. 

RANGE. — Florida: Jacksonville (Ashmead) ; Lady Lake, Tavares, Bowling Green, Fort Meyers. Probably confined to the most southeastern part of the United States. 

I have not seen types, but I have insects and galls deter- mined as this species by Ashmead, and insects I collected at Tavares, Florida. It may be that more than one variety is represented by the other localities I have listed. In the material I have seen the antenna has 13 segments, not 14 as Ashmead stated, and the areolet is not obliterated as originally described but is small and bounded in part by a very faint vein. The insect is distinguished from restrictus by its smaller size, the large amount of yellow on the legs including the coxae, and the smaller areolet. 

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 (Dolichostrophus) dubius

GALL. — A small, egg-shaped capsule; monothalamous, thin-walled, entirely hollow, 2.0-3. 0 mm. long by 1.0 mm. in diameter, pointed at one end, drying light yellowish brown, scatteringly set with short wool. On the edge of the leaf or on the aments of white oaks (figs. 53, 54). 

RANGE. — Massachusetts to California. Probably thruout North America, wherever white oaks occur. 

All of the known varieties are bisexual, in spring galls, the insects emerging not very late in the spring. The galls of only a single form are known, the other insects having curiously turned up in collections of galls of other Cynipidae. Probably the galls of all varieties are so small and simple as to be overlooked in collecting. 

Neuroterus dubius variety clarkeae

GALL. — As described for the species; on the edge of the leaf, or on aments of Quercus alba (figs. 53, 54). 

RANGE. — Massachusetts: Magnolia (Clarke coll.). New Jersey: Broadway. Probably confined to a more northeastern portion of the United States. 

Beutenmuller’s Massachusetts material emerged in late May and early June; my New Jersey material emerged soon after collecting on May 19, 1920. The type galls occurred on leaves ; my material was on the aments ; I have not been able to examine the type material, but I think there can be no question of the varietal identity of my own insects. The galls are very similar to most anther galls, but bear a scattered wool. The occurrence of the type galls on leaves and of my galls on aments is merely typical of the gall polymorphism in this subgenus, where any young tissue may be attacked, the insects showing little specialization in their choices of points of oviposition. 

Neuroterus (Dolichostrophus) dubius

GALL. — A small, egg-shaped capsule; monothalamous, thin-walled, entirely hollow, 2.0-3. 0 mm. long by 1.0 mm. in diameter, pointed at one end, drying light yellowish brown, scatteringly set with short wool. On the edge of the leaf or on the aments of white oaks (figs. 53, 54). 

RANGE. — Massachusetts to California. Probably thruout North America, wherever white oaks occur. 

All of the known varieties are bisexual, in spring galls, the insects emerging not very late in the spring. The galls of only a single form are known, the other insects having curiously turned up in collections of galls of other Cynipidae. Probably the galls of all varieties are so small and simple as to be overlooked in collecting. 

Neuroterus dubius variety digressus

GALL. — Not known. On Quercus lobata. 

RANGE. — California: Coalinga. Probably occurs thruout the range of Q. lobata in Central California. 

The type material was found among a lot of insects from ament galls of Neuroterus pacificus, and the galls of digressus were not identified, probably because they are small, simple cells in the aments, in the accompanying buds, or on the young leaves. The insects emerged sometime before the end of March in 1920. Altho geographically distant from the range of variety dubius, there is no doubt that digressus belongs to the same species. 

Neuroterus dubius variety dubius

GALL. — Not known. Probably similar to those described for the species. Apparently on Q. stellata.
 
RANGE. — Connecticut: Waterbury. Probably confined to a more northeastern portion of the United States.

The above descriptions are made from a paratype female and a paratype male. This insect was obtained by Bassett from a box of galls of Andricus pruinosus, and he did not find galls which might have been made by the Neuroterus. Pruinosus comes from Quercus stellata, and probably dubius has the same host. 

Neuroterus (Dolichostrophus) irregularis bisexual form

GALL. — A thick, leaf blade swelling, involving both surfaces of the leaf, with the larval cells mostly deeply imbedded. Polythalamous. Galls generally elongate, oval, as thick as wide, up to 5. mm. wide by 15. mm. long, several galls often fusing; green, very succulent, shrivelling considerably upon drying; solid, the larval cell with a distinct but inseparable lining, lying mostly below the surface, only rarely evident on the surface. Smooth, naked, and larger when on Quercus alba; very pubescent and smaller when on Quercus stellata (fig. 52). 

RANGE. — Ontario to Texas. Probably thruout eastern North America. The galls of this species appear on the very young, un- folding leaves, and very quickly mature, the insects emerg- ing before the leaves are fully expanded. This, of course, is earlier further south, April and May, to early June in New England. The galls become shrivelled and decayed, and only a few remnants will be found later in the summer. Of 430 insects which I have bred for all varieties, 167, or 39 per cent, are males. This is higher than the percentage for the related decipiens, but may show a tendency toward the reduction of the male. 

This is clearly the eastern equivalent of Neuroterus decipiens, but the two are distinct species. The present species is closely related to Neuroterus minutus, but irregularis, altho one of its varieties is the type of the subgenus, is certainly an extreme in Dolichostrophus. Irregularis varieties are very poorly defined, and rest in all but one instance on color and size characters, the males being most distinctive. Apparently the eastern third of the United States does not possess the sharply defined faunal areas of the Pacific Coast, and the more uniform geography of the east would lead one to expect this. Further, the eastern oaks are in many instances more closely related than those of the west, and host isolation, in irregularis at any rate, does not appear to have developed distinct insects. These conditions, combined with considerable individual variation, so obscure the group variation that I would hesitate to determine single specimens of the females and sometimes of the males of varieties of this species. 

[Kinsey describes several varieties of N irregularis, all of which are still synonyms of the species today. See paper for more information.]

Neuroterus (Dolichostrophus) minutus bisexual forms

GALL. — An inseparable swelling, varying greatly, depending upon the part of the plant affected; on Quercus alba, Q. bicolor, and probably related white oaks. 

RANGE. — Connecticut to Pennsylvania. Probably thruout eastern North America. 

This species is the eastern equivalent of Neuroterus quercicola, differing mainly in having a lighter color, the abdomxen not produced, and the first abscissa slightly arcuate. The galls of variety minutus resemble leaf galls of quercicola. Neuroterus irregularis is closely related to minutus, but the males of the two are very distinct. The two varieties of minutus have what might appear to be radically different galls, but several similar cases of gall polymorphism are recorded in this paper for this genus. The galls of variety pallidus are "monothalamous" clustered, seed- like, anther galls; those of minutus are irregular, polythalamous, petiole or vein swellings. The diversity is probably the result of the relatively simple gall-producing physiologies of the insects and of the differences of the affected plant tissues. A consideration of gall polymorphism, and of the nature of anther galls, will be found in the introduction to this paper. That one of the varieties should be known only from the leaf galls on Q. alba, the other only from the ament galls on Q. bicolor may evidence merely our lack of sufficient data. Both galls may be found on both oaks, but if this is not shown, then an examination of the vernations of the buds in which the insects oviposit may explain the matter. There is little chance of there being any great differences in the physiologies of the two varieties. Each of the two described varieties is confined, it would appear, to a single species of oak. About 40 varieties should occur on related oaks in the eastern half of North America. The bisexual insect is short-lived, its gall evanescent, and consequently not often collected. An alternate, agamic generation, producing perhaps a stem or leaf swelling, probably exists, but I fail to recognize this form among any of our described species of Neuroterus, 

Neuroterus minutus variety minutus

GALL. — An elongate, irregularly cylindrical swelling of a petiole or midvein. Polythalamous, with a moderate number of cells. Each gall irregularly cylindrical, elongate, up to 5. mm. in length, sometimes several galls more or less fused; covered with normal tissue and an additional pubescence, pinkish when young, drying brownish. Internally more or less solid, with the larval cells rather closely packed, without distinct cell walls. On petioles and leaf veins, more or less dwarfing and deforming the leaf; on Quercus alba (figs. 45, 46). 

RANGE. — Connecticut: Waterbury (Bassett). New York, New Jersey, Pennsylvania (Beutenmuller). Probably confined to Q, alba in a northeastern part of the US.

Bassett described this gall as appearing as soon as the oak leaves begin to expand, in April or May, and maturing within a few weeks, by the time the leaves are fully expanded. The above descriptions are made from a good-sized series of types. 

Neuroterus quercicola variety congregatus bisexual form

GALL. — Typical for the species ; described as a terminal twig swelling, 6.-8. mm. in diameter, with larval cells developing within the bud, and covered with a pubescence; or merely larval cells buried in the twig; on Quercus (Gambelii?) . 

RANGE. — Colorado: Manitou (Gillette). Probably confined to a limited area of the foothills east of the Continental Divide. 

Gillette's insects were taken at Manitou, Colorado, emerging from May 8 to 17 ; they were all males. The host was not named, but it was probably Quercus Gambelii, which is the common oak about Manitou. Not only stems and buds, but also flowers and leaves should be involved in the galls of this bisexual form. Gillette compared his galls to those of N. vesicula, but the two are very different. There is no question of the relation of congregatus to the Pacific Coast varieties of the species. The male of this variety is the darkest in the species, furnishing another instance of the melanism common at Manitou. 

Neuroterus quercicola variety pubescens, new variety
agamic form

GALL. — As described for the species. A moderate-sized mid-vein or petiole swelling, woody, packed densely with larval cells, covered with a bluish gray, dense, short pubescence; on leaves of Quercus grisea. 

RANGE. — Arizona: Globe, Safford. Probably confined to the mountain country just south of the Colorado Plateau. 

This gall is rather distinct from others of the species in its coat of bluish gray pubescence. It is of interest as an agamic generation in a leaf gall; the only other agamic form known inhabits twigs or acorns, but the evergreen leaf of the host of the present variety allows the fall and winter form to survive on the leaf. This form may also occur in twigs with or without producing a gall. The bisexual form probably occurs in a similar gall on the leaf. 

Neuroterus quercicola variety quercicola 
bisexual form

GALL. — Typical for the species; a leaf midvein swelling; on Q. Gambelii. 

RANGE. — Utah: a southern part (Bassett); Salt Lake City (thru C. T. Dodds) . Probably confined to a region in Utah. 

Weld's galls, collected on July 2, 1911, gave adults July 30. This is considerably later than the March and April emergence of variety pacificus further south, and shows the considerable dependence of cynipid development upon the development of the host. The above descriptions are made from paratypes. The insect differs only slightly from pacificus, but has not gone the way of the usual synonomy. The gall is very much like that of pacificus on Q. Douglasii. It is possible that the aments of garryana will show galls of variety washingtonensis similar to the ament galls of pacificus on Q. lobata. The alternate generation of this insect may be either a similar leaf swelling, a woody stem swelling, or a cell in an acorn cup, and I have collected the latter gall at Ashland, Oregon.

Neuroterus quercicola variety fragilis

GALL. — Typical for the species, rather small, on the midveins, involving the blades; an irregular, polythalamous swelling up to 6 mm. in diameter; on Quercus dumosa. 

RANGE. — California: San Diego (vicinity) (Bassett) ; Pasadena, Upland. Probably thruout southern California from Palo Alto and El Portal south, wherever Q. dumosa occurs. 

I have not seen insects of this variety, and have depended upon the meager, original description for my note on the adult. I have galls from Pasadena and Upland which agree with the original description and with the figure given by Beutenmuller (1910). The Beutenmuller material, altho not definitely designated, would appear to have come from Bassett. The small galls with small exit holes would favor Beutenmuller’s 0.7 mm. instead of Bassett’s .05 inches for the length of the insect. My galls, as well as Beutenmuller’s, are from Q. dumosa; Bassett recorded the host as ‘'a small oak in southern California, probably Q. virens or a related species.” Wold, in McCracken and Egbert, considered fragilis and pacificus synonyms, and those authors, confusing the two in- sects, intimate that Q. Douglctsii and Q. lobata are the hosts of fragilis. Of course neither Douglasii nor lobata occur within nearly a hundred miles of the type locality of fragilis. Dumosa and Engelmannii are the only white oaks near San Diego, and since dumosa is the only small oak in accord with Bassett's description, this would appear to be the host of this variety. I have never seen the same variety of a cynipid on Q. lobata in Central California and on Q. dumosa in southern California, and there is hardly a chance that fragilis and pacificus are not distinct. 

Neuroterus quercicola variety pacificus bisexual form pacificus

GALL. — Typical for the species, varying as to its location on leaf veins, petioles, young stems, or flower stems, this location apparently determined by the species of the host, as follows: 

Q. Douglasii Gall: Elongate swelling of a leaf vein, involving the blade; up to 25. mm. in length and 10. mm. in diameter, somewhat irregular, protruding largely from the under surface of the leaf, smooth, green, succulent when fresh, drying dark brown, rather hard and papery, without much shrivelling (fig. 60).

RANGE. — California: Cupertino, San Jose (Fullaway); Stanford University, Sunol (McCracken) ; Metz (in coll. Univ. Calif.) ; Mt. Diablo (F. A. Leach coll.); Zelzah, Gilroy (Redwood School), Coalinga (Al-calde), Three Rivers, Exeter, Paso Robles, San Luis Obispo, Byron, Galt, Redding. Certainly thruout Central California and possibly wherever Q. Douglasii and Q. lobata occur. 

Neuroterus quercicola variety pacificus bisexual form pacificus

GALL. — Typical for the species, varying as to its location on leaf veins, petioles, young stems, or flower stems, this location apparently determined by the species of the host, as follows: 

Q. lobata Gall: Elongate swelling mainly of the flower stem, beset with dwarfed clusters of stamens; involving the young twig, petioles, and leaf blades to a minor degree; elongate, but very irregular, up to 15. mm. in length by 8. mm. in diameter, greenish or yellow when fresh, drying light yellowish brown and shrivelling considerably upon aging (fig. 63). 

RANGE. — California: Cupertino, San Jose (Fullaway); Stanford University, Sunol (McCracken) ; Metz (in coll. Univ. Calif.) ; Mt. Diablo (F. A. Leach coll.); Zelzah, Gilroy (Redwood School), Coalinga (Al-calde), Three Rivers, Exeter, Paso Robles, San Luis Obispo, Byron, Galt, Redding. Certainly thruout Central California and possibly wherever Q. Douglasii and Q. lobata occur. 

Neuroterus quercicola variety pacificus 
agamic form varians Kinsey

Neuroterus quercus-batatus (woody gall only)
Neuroterus pacificus (woody gall only)
Neuroterus varians
Neuroterus cupulae

GALL. — A slight swelling of the affected part, the larval cells with a distinct but inseparable lining; galls of two types as follows: 

Stem Galls: Short, blunt, irregular swellings; up to 35. mm. in length, and 12. mm. in diameter; very rough, covered with bark of normal color, also involving distorted buds, petioles, or leaves; some- times not producing much of any swelling. Internally filled with closely compacted, oval larval cells, located mostly toward the periphery (figs. 51,55). 

Adults emerged from twig galls at Byron on March 21, 1920, a couple of days after collecting, and from both twig and acorn galls on March 7, 1920, at Paso Robles. The twig galls which Fullaway had, bred adults on February 15 in the laboratory. All of the insects had previously emerged from twig galls I collected on March 3, 1920, at Zelzah, and March 23 at Three Rivers. Emergence, then, occurs early in the spring before the buds have opened, and it is in these closed buds that the insect oviposits to produce the flower stem, and leaf vein galls of form pacificus. 

There can be no question of the identity of varians and cupulae. I described these as distinct species primarily because the galls of the two are so very different that the possibility of their identity never was entertained. I never compared the two descriptions, and only a revision of the whole genus, analyses of subgenera, and the writing of comparative descriptions, Anally showed me the mistake. This is an indictment of the publication of miscellaneous new species, and justification of the revision of whole groups at a time. Varians and cupulae are synonyms, not because the insects largely resemble each other, but because detailed examination of large series of the types of the two fails to disclose a single point of constant, group difference. Insects were emerging from both kinds of galls at the same date from the same trees at Paso Robles in 1920. 

Here is one of the most remarkable cases known of one cynipid producing two or more distinct kinds of galls on different parts of the host. Several other cases are pointed out in this paper for the genus, but otherwise few cases of gall polymorphism are known in the Cynipidae. Varians lives either in twigs or acorn cups. In the first instance the galls are polythalamous swellings packed with larval cells, while in the second instance they are single, scattered larval cells which produce almost no swelling. So does the plant tissue determine the character of the gall! It might be suggested that the two insects, altho alike morphologically, are different physiologically as evidenced by their different points of oviposition, but such matters cannot be investigated with our present means. Meanwhile it appears probable that insects from either type of agamic gall lay eggs for either type of bisexual gall, apparently due to the lack of a peculiar physiology which might restrict oviposition to a single point on the plant. 

Range: CA, thruout central CA and possibly wherever Quercus douglasii and lobata occur.

Neuroterus (Dolichostrophus) rileyi 

GALL. — An irregularly continuous stem swelling. Polythalamous. The swelling rather restricted in size, 10. mm. long or less, raised 5.0 nun. or less above the normal stem, asymmetric on the stem, but often many swellings fused to make a more or less continuous mass 80. mm. long and 12. mm. wide, lying all around the stem; covered with normal bark which is sometimes rather loose and wrinkled. Internally compact woody, the larval cells near the surfaces, with a distinct but wholly inseparable lining. On chestnut oaks (fig. 62). 

RANGE. — Massachusetts to Colorado; possibly transcontinental. 

Neuroterus rileyi variety atripleurae, new variety
agamic form 

GALL. — As described for the species; of medium size, the swelling elevated to 2.5 mm. above the stem. On older twigs of Quercus Prinus. 

RANGE. — Oklahoma: Pawnee. Probably thruout the oak areas of Oklahoma, Arkansas, western Louisiana, and eastern Texas. 

Live adults were in these galls on April 28, 1920, while some had already emerged at that date. This is the agamic generation, and the alternate should be very similar, bisexual, in smaller galls on younger twigs, starting growth in May and emerging in July. 

Neuroterus rileyi variety mutatus, new variety
agamic form 

GALL. — As described for the species, but large, woody, up to 12. mm. in diameter (whole stem) ; on the stems of Quercus Muhlenbergii. 

RANGE. — Texas: Hamilton’s Pool (Travis Co.). Probably confined to an area in Central Texas. 

The occurrence of this insect on a distinct host in a very well-defined faunal area has clearly favored the development of a distinct variety. The gall is so much larger than in other varieties that it somewhat resembles galls of N. batatus.

Neuroterus rileyi variety rileyi
agamic form 

GALL. — As described for the species; large, the swelling elevated above the stem to 3.0 mm. On older twigs of Quercus prinoides. 

RANGE. — Ohio: North Bend (Riley in Bassett). Indiana: (Cook). Illinois: (Beutenmuller) . Missouri: Cadet (Riley in Packard). Iowa; (Cook). Probably confined to a region of the Middle West north of Oklahoma. 

Riley recorded this insect emerging in April and early May, and Cook added that the galls form in late summer, so the insect overwinters in the galls. This is in agreement with the occurrence of other agamic forms in the genus. The alternate generation will be very similar, the insect possibly a little smaller, the galls smaller and on younger twigs, beginning growth in May, with the insects emerging in June or July. 

Neuroterus rileyi variety thompsoni Kinsey
bisexual form 

GALL. — -As described for the species; small, the swelling elevated above the stem, raising the bark to 1.0 mm. On younger twigs of Quercus prinoides.

RANGE. — Massachusetts. 

Thompson stated that these galls form in May. This is a bisexual generation, and adults, if typical for this genus, would develop very quickly, emerging before midsummer. We do not have the emergence date for this material, but it is probably June or early July. The agamic generation would form after mid-summer and emerge early in the following spring, as for variety rileyi.

Neuroterus rileyi variety virgens Gillette
agamic form 

Neuroterus virgens

GALL. — Probably as described for the species; the types small, with only a slight swelling. On twigs of Quercus Gambelii.

RANGE. — Colorado: Manitou (Gillette). 

Gillette’s insects were all females, not males as Beutenmuller stated. They were reared between May 8 and 13. The host was not recorded, but was probably Q. Gambelii, the common oak of the region. I have not seen material certainly known to be types, but I have seen material from the U.S. National Museum collected by Baker and determined by Baker; Mr. Weld says that these insects agree with the type of virgens. This is the only record of a variety of rileyi occurring on other than chestnut oaks, and the only record of the species west of the 100th meridian. This may suggest that the species occurs on white oaks of several groups and that it is transcontinental. 

Neuroterus vesicula

Gall.--A small, thin-shelled, globular bud or bark gall. Monothalamous, up to 3 mm in dia (bark galls smaller); rather thin-walled, quite globular, the bark galls more solid; almost smooth, but microscopically pebbled; bark galls colored with light buff yellow and brownish red in splotches; internally entirely hollow, without a distinct larval cell. Inserted in the slightly ruptured bark of stems; on white oaks and chestnut oaks.

Neuroterus vesicula variety cerinus
[Bark gall on Q stellata, possibly breviloba]

GALL. — A bark gall, as described for the species. On stems of Quercus stellata (and Q. breviloba?) (fig. 48).

RANGE. — Texas: Austin (Patterson coll.). 

Dr. Patterson is to be credited with the discovery and breeding of this interesting insect. He reports this gall as appearing to be several weeks old on February 1, 1923, the adults emerging about the first of March in 1921, and on February 23 in 1922, fully half of the adults having emerged by February 26, 1922. From these dates, this should be the agamic, winter generation of some variety, as discussed in the introduction to this species, but Dr. Patterson assures me that he has secured 5 females and 6 males from these galls. The male does differ from the female in antennal color more than the amount of secondary sexual differences usual in the species, and at first I doubted the connection of the two, but the rugose scutellum and the narrowed foveal furrow show the relationship. The gall is very similar to galls of the other forms but is unique in its occurrence on the bark of stems and is (consequently?) of different texture and color. This is one of the most interesting of Dr. Patterson’s many valuable finds. 

Neuroterus verriicarum variety floccosus (Bassett) 

Cynips floccosa Bassett, 1881
Neuroterus floccosus Mayr, 1881

GALL. — As described for the species; averaging rather large; on Quercus bicolor. 

RANGE. — Ohio: northern (Bassett). Illinois? (Beutenmuller). Probably confined to a northern portion of the Middle West.

I have examined 203 insects from the Bassett ‘"type” material at the Philadelphia Academy; of these, only 41 are true floccosus while 162 represent variety pernotus, probably from Q. bicolor at Waterbury, Connecticut. As is well known, it was often Bassett’s custom to place all of his material of a species in a single box, and apparently this happened in the case of floccosus. Of the two varieties among the Bassett types, one agrees in its dark colorings, larger size of areolet, and greater length with the Bassett description of material from northern Ohio; the other does not agree with the description of floccosus and does agree with types of pernotus which is a New England variety. Very likely Bassett obtained his pernotus material near Waterbury, Connecticut. The northern Ohio material must stand as floccosus even tho it is not as abundant among the Bassett “types”.

[Neuroterus verrucarum variety pernotus, new variety](https://www.biodiversitylibrary.org/page/53512324#page/330/mode/1up)

Neuroterus floccosus Beutenmuller, 1892

GALL. — As described for the species; larger than the galls of other varieties; on Quercus bicolor. 

RANGE. — Massachusetts: Worcester? (Thompson coll.); Boston (Clarke); Springfield (Stebbins) ; Forest Hills. Connecticut: Waterbury (in Bassett collection); New Haven (Felt in N.Y. State Mus.). New York: New York City (Beutenmuller). New Jersey: Broadway, Carmel. Probably confined to a northeastern area of the United States

Neuroterus niger variety pattersoni, new variety
bisexual form pattersoni, new form

GALL. — Circular, not elongate, very slightly smaller than nigripes, with more well-defined boundaries and without a trace of a central point on the upper surface. On Quercus stellata (fig. 43).

RANGE. — Texas: Austin (Patterson coll.).

Dr. Patterson, for whom this variety is named, collected and bred the type material. He states that in 1921 the gall first appeared March 10, the adults beginning to emerge on May 7. Dr. Patterson sent me records (a year ago) of breeding 453 females and 450 males, making the important observation that a single leaf of galls usually yields only a single sex of the wasp. The detailed record of these observations I should leave for Dr. Patterson to publish. It would appear that the agamic females are of two sorts, either female- or male-egg-producing. What is evidently the agamic form of pattersoni is described in the following paragraph.

Neuroterus contortus

GALL. — An irregular stem swelling, wholly inseparable. Polythalamous. Individual galls up to 20. mm. long and 8. mm. wide, but sometimes several galls are closely adjacent and more or less fused. Externally very rough, small, irregular, raised spots indicating some of the larval cells; covered with greenish, young bark, drying browner. Internally woody, most woody centrally, with a great many, densely packed, small larval cells, 1.7 mm. long by 0.7 mm. in width, mostly toward the surface; the lining distinct but wholly inseparable. On young stems, involving young petioles and deforming the young leaves; at the crowns (or on roots?) of Quercus breviloba (figs. 58, 59).

RANGE. — Texas: Austin. Probably occurs thruout eastern Texas and adjacent parts of Louisiana and Oklahoma. The agamic generation is known from galls and adults obtained by Weld in 1917, and from a quantity of material Dr. J. T. Patterson has bred. Several hundred insects of the bisexual generation were bred by Dr. Patterson in the spring of 1922. I first connected the alternate generations of this insect on the basis of the complementary dates of development and the extremely close similarity of the insects and galls, and this similarity is enough to make the relation unquestionable. Dr. Patterson confirms this by his experimental data.

The agamic generation starts growth in April; Dr. Patterson describes the galls as nearly fully formed by the last of April, with small larvae in the galls by July; Weld found pupae on October 16 and 30, with live adults in the galls on December 1 and 12. Emergence is in the relatively mild winter season of Texas or in the early spring, from before the last of January to after the 7th of February, according to Dr. Patterson’s records. Dr. Patterson states that he has secured 10 males with 231 females of this agamic generation, but that these males are unable to mate with the females, altho they attempt to copulate; the females appear to have completely lost the mating instincts, as have the males to some degree. These males are apparently functionless, which is a most interesting case of this sex persisting as a generation becomes agamic. I have seen four of these males. The bisexual generation develops quickly in the spring. Dr. Patterson obtaining adults on April 3, 1922. He has sent me almost three times as many males as females, so probably the sexes occur in about equal numbers. The galls of the two generations are similarly located at the crown of the tree, and differ very little in structure. I do not see any differences between the insects of the two except in the larger size which is almost always correlated with agamic reproduction of Cynipidae. The close similarity of the alternates is one reason for placing contortus in this genus. This is the only root gall yet known in Neuroterus, but the gall is sometimes on stems at the crown of the tree. Weld records a specimen of this species obtained from Palestine, Texas, on Quercus stellata. It may belong to a distinct host variety. Probably still other white oaks of eastern Texas, Louisiana, and Oklahoma are hosts for this species.

Neuroterus contortus bisexual form principalis, new form

GALL. — Not greatly different from the gall of the other generation; somewhat smaller and more ragged with deformed leaves and twisted petioles of young leaves (fig. 58).

The Gall Wasp Genus Neuroterus