Kokkocynips decidua (agamic)

Acraspis quercushirta (agamic)

Neuroterus quercusbatatus (agamic)

Callirhytis scitula (sexgen)

Neuroterus quercusbatatus (sexgen)

Neuroterus quercusirregularis (sexgen)

Callirhytis clavula

Callirhytis quercusventricosa (agamic)

Andricus quercusfrondosus (agamic)

Zapatella quercusphellos (sexgen)

Diastrophus potentillae

Amphibolips ilicifoliae (sexgen)

Andricus quercusformosus (agamic)

Cynips quercus decidua, n. sp. [described from gall only without insect]

Quercus rubra. 

Clusters of seed-like bodies, often thirty or forty together rowing on the midvein on the under side of the leaves of Q. rubra. The larger cells are about the size of a grain of wheat. They are smooth, greenish-white, the apex enlarged, and would remind a botanist of the sessile stigma of some flowers. Gall fly unknown. 

My specimens were collected about the first of October, and were then fully grown. Some had fallen to the ground, but on cutting open a large number I could not detect any larvae. The leaf stems and twigs were placed in water to keep them green, but the galls soon dried and many fell off. A few fell into the water, and these not only kept green, but on opening them a few days since, half-grown larvae were found. From this I infer that the growth of this species is dependent upon the galls being covered in the earth. 

Cynips quercus hirta n. sp.

Quercus montana. Hard, round galls, .25 of an inch in diameter with a finely papillose surface and a solid radiated cellular structure; growing sometimes on the upper, but as often on the under side of the leaf; attached to the larger veins by a very short pedicel. 

These galls are rarely met with, and I have seldom found more than one on a leaf. In a single instance there were three on the same leaf, two on the under side and one on the upper. My specimens were found in October and contained perfect insects. Through the gall of several, gathered October 20th, the insect had eaten a passage but they still remain in the galls. 

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.

C. q. scitula, n. sp.

There is little or no apparent difference [between this and Neuroterus quercusbatatus] in the gall than pertains to the different species of oak on which they grow. 

Quercus tinctoria [velutina]. 

Woody, tuber-like galls, growing on the green branches of Q tinctoria [velutina], sometimes simply an enlargement of the limb, at others entirely checking its growth and covered with leaves. They are from three-fourths to an inch and a half in length, and rather more than half an inch in diameter at the base, tapering to a cone-like point.

Cynips quercus majalis n. sp

QUERCUS ALBA. Flat, green, succulent galls, often of a very irregular outline, and from one-fourth to more than an inch in diameter, the vertical diameter from one-fourth to three-eighths of an inch, growing on the leaves of the white oak, and producing, according to the size, from two or three, to more than a dozen gall-flies. The flies escape from the galls in June, through the upper or under surface. The water that enters the cavities the flies have left causes the galls soon to decay and drop off, but a few change to a dry pith-like substance, and remain on the tree through the summer. These might be taken for a different species, as they generally contain larvae, but having reared a few Spalangia (?) from such galls, I infer they are all parasitic. 

This species is closely related to C. q. irregularis O. S. but grows on a different species of oak, and Baron Osten Sacken to whom I sent specimens, thinks it may be specifically distinct from that species, which I have not yet seen. The imperfect condition of his only specimen of C q. irregularis renders a satisfactory comparison impossible, and acting upon his suggestion, I describe it as C. q. majalis n. sp. Several hundred males and females. 

Cynips quercus tuber [contains the [first description](https://www.biodiversitylibrary.org/item/23810#page/705/mode/1up) of the anatomy of the true inducer]

Nine specimens. 

I have a single male gall fly reared from the same galls, but it differs so much from the female that I am inclined to think it belongs to a different species. 

Though the galls are very much alike, the venation of the wings, the pleurae, and several other points of difference mark it as a distinct species from C q. similis. Dr. Fitch has figured the gall of his C. q. tuber which he found "quite common particularly upon the soft and tender limbs of young (white oak) trees" (N. Y. Rep., Vol. 2d, No. 309). He describes (1. c. No. 310) the galls of C. q. arbos as "swellings similar to that above described, growing on the tips of the limbs of aged and large white oak trees." 

My galls, which are probably identical with his C. q. tuber, were gathered from low, shrubby white oak bushes, though I have often Been precisely similar ones on large trees. Dr. Fitch's descriptions of the flies from C. q. tuber or C. q. arbos will apply, so far as they go, to either the gall flies, or to the guest flies as the inquilinae are termed by Mr. Walsh. For the reasons that follow, I am led to think that the species he described under the above names are both inquilinious species. 

1st. My galls were gathered about the 20th of June, and were then green and soft like the wood of the young shoots on which they grew. The insects were then in the pupa state, and the imago came out early in July. The gall from which Dr. Fitch's C. q. arbos was reared was found in March, and were of the preceding year's growth, as were also those of C. q. tuber, if we may judge from his description of the color of the gall, which will only apply to the galls long after the true gall- flies have left them. 

2nd. My galls gathered from young white oaks, and which answer perfectly to his figure and description of C. q. tuber, produced females with 13-jointed antenna?, while his have but 12 antennal joints. 

3rd. I have gathered several hundreds of these galls in the autumn, winter and early spring within the last two or three years, but have never reared from them one true gall-fly, though they have produced large numbers of male and female guest-flies — the male answering perfectly to Dr. Fitch's description of C. q. arbos. The female he had not seen.

4th. The galls I collected in June have not yet produced any guest- flies, but cutting open several to-day I found in one a large living larva — the others were empty or contained dead gall-flies that had not been able to eat their way out of the dried gall. From the above facts I am forced to believe that the galls C. q. tuber and arbos Fitch are both produced by the same fly, and that it is the same species that I have described above and for which I retain Dr. Fitch's name, C. q. tuber. Dr. Fitch has, no doubt, described two distinct flies, for Mr. Walsh, who has devoted much attention to the guest-flies of the oak galls, finds that not only do some species live in several different species of galls, but that the same kind of gall may produce more than one species of guest-fly. (Proc. Ent. Soc. Philad. Vol. 2d, p. 465.) 

Mr. Walsh, in the article referred to, mentions other of Dr. Fitch's , species which he is satisfied are inquilinae, and not the producers of the galls from which they were reared. (See pp. 464-5, 484 and 494.) His remark that "C. q. tuber Fitch is in all probability a guest-fly," escaped my notice till this moment. 

Callirhytis quercus ventricosa n. sp.

Galls growing in clusters from three or four to a dozen together on the limbs and occasionally on the trunks of young shrub oaks. They are cone-shaped, truncate at the base, the apex often prolonged in a slender, recurved point. They are from four to five- eighths of an inch long, and from one-fourth to three-eighths in diameter at the base. When green, often of a deep red color; when dry, brown or black; very hard, enclosing a nearly free larval cell like that of C. q. globulus. Fitch. 

My galls were collected in June. The flies were found to be fully developed in October. They were cut out, else they would probably have remained in the galls until spring. 

Cynips quercus frondosa, new species
New species of galls, the flies of which are as yet unknown to me 

Quercus chinquapin [muehlenbergii]

Gall a cone-like body, developed from the axillary leaf-buds, and covered when green and often when dry with a dense, rose-like cluster of imperfectly developed leaves. The cell containing the larva smooth, shining, oval, about one-eighth of an inch long, half immersed in the apex of the cone.

These singular and very pretty galls are developed after the summer growth of the tree is completed, and the axillary buds are formed. The sting of the insect causes the buds that would otherwise remain undeveloped till the following year, to develop in the autumn in the abnormal manner described above. 

The rudimentary leaves are green, ligulate, and the more perfectly developed galls resemble, more than anything else I can think of, the flowers of the common Artemesia of the flower garden. They are not common, but I have several times met with them, and the clump of oak bushes from which my specimens were gathered was covered with them. The larvae are now fully grown. On the same bushes I found a gall like C. q. globulus Fitch, — and several dry, brown galls on the petioles of the leaves, apparently those of C. q.petiolicola. 

Cynips quercus similis n. sp.

 QUERCUS ILICIFOLIA. Club-shaped, woody galls, growing on the ends of the small limbs. Apex blunt and generally turned to one side, covered in summer with a few leaves and containing one, and occasionally two or three larvae. It is strikingly like that of C. q. tuber of Fitch, but produces a fly which though closely related, is evidently a different species.

Diastrophus potentillae n. sp.

Galls On Potentilla Canadensis. They are from .3 to .5 of an inch in diameter, and rather longer than thick, growing in the axils of the leaves ; of a soft spongy consistence when dry, and each contains a single cell in shape and size like the nucleus of C. q. globulus, though not, like that, free from the substance in which it is enclosed. They are rather rare here (Conn.), but I saw large numbers of them in the northern part of Berkshire Co., Mass., last summer. The fly came out May 20th from galls of the previous year's growth. It is much like D. nebulosus 0. 8., but Baron Osten Sacken has compared it with this species, and pronounces it distinct.


Cynips quercus ilicifoliae n. sp.

Quercus ilicifolia. Elongated, fusiform galls growing on the upper side of the leaves of Q. ilicifolia, and standing erect, or nearly so — sometimes entirely preventing the development of the leaf, and apparently growing out of the petiole. The central nucleus containing the larvae, is kept in place by radiating woody fibres as in C. q. inanis 0. S. The largest galls are two inches in length and seven-eighths of an inch in diameter ; average size about one and three-fourths inches long, and three-fourths in diameter. Apex rather longer and more slender than the basal portion, and often considerably curved. 

These galls are of the same dark green as the leaves. Many are found very much smaller than those described above, but they produce parasitic flies. Baron Osten Sacken writes me that he met with numbers of these galls in Pennsylvania several years ago. They are rather rare here (Conn.)

Cynips quercus formosa n. sp.

Quercus rubra. A cluster of forty or fifty elongate-ovate galls on a branch of a young red oak tree. They are from three-fourths of an inch to an inch in length, and a half an inch in diameter in the middle, tapering to a point at the ends; covered with a short, velvety pubescence, and when dry, ridged like a melon; the inside, a cork-like substance adhering closely to the larval cell, and divided lengthwise into many parts like the dissepiments of the seed-vessels of various kinds of plants; monothalamous - the cell one-tenth of an inch long.

The flies have not yet left the gall (Nov. 25) though they have been in the imago state for several weeks, and crawled about actively when the galls were opened. They may be imprisoned by the hard dry gall, but I am inclined to think, that, like some other species, they remain in the galls in the perfect state through the winter and come out early in the spring.

The galls of this species are very rare. I have found only two clusters, and one of these was much eaten by some Lepidopterous larva, and the larvae of the true gall fly were destroyed. Only a part of the galls in the other cluster were developed as described above; the smallest were not larger than grains of barley, but contained larvae, and have produced true gall flies. Their diminutive size was owing, apparently, to their being closely crowded. 

This and the species next described, C. q. ventricosa n. sp., are readily distinguished from any other American species yet described, by the female, (male as yet unknown,) having fifteen distinct antennal joints. Dr. Fitch (N. Y. Rep. Vol. 2. No. 309) speaks of having, in his collection, a female gall fly with fifteen jointed antennae, but he does not describe it, nor the gall from which it came. 

Westwood (Syn. Gen. Br. Insects) does not characterize any genus of the family Cynipidae as having more than the female 14, and the male 15 antennal joints — but the male of my C q. singularis* (Proc. Ent. Soc. Pliila. Vol. 2nd. p. 32(3) has 16-jointed antennae, and C. q. scitula — a new species described in this paper — also has the same number. The females of both these species have only 13 joints, the terminal one long and connately divided in the middle. 

C. q. formosa and the species next described are evidently closely related, for besides the 15-jointed antennae of the 9 there are other points of resemblance; and the remarkable difference in the colors of the two species, the ripple-marked thorax of C. q. formosa, and the widely different galls from different species of oak, are the most marked specific characters. The shape of the abdomen of both species is peculiar; different in form, and, I think, in structure, from any other species I am acquainted with, but I have not yet sufficiently studied the structure to describe it well, and have simply, in my description, noticed the vertical diameter as equalling or exceeding the length. 

Descriptions of several new species of Cynips and a new species of Diastrophus