Andricus seminator

Cynips seminator

Nebraska

Cynipidae

Callirhytis

Quercus alba

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Quercus michauxii

Quercus montana

Cynipid galls of the eastern United States

50 common plant galls of the Chicago area

Field Book of Insects: With Special Reference to Those of Northeastern United States, Aiming to Answer Common Questions

An illustrated catalogue of American insect galls

Galls and their architects

Callirhytis seminator (sexgen)

Cynips seminator

One of our smallest gall-flies may be called Cynips seminator, or the sower. She lays a great number of eggs in a ring-like cluster around the small twigs of the white oak, and her punctures are followed by the growth of a rough or shaggy reddish gall, as large sometimes as a walnut. When this is ripe, it is like brittle sponge in texture, and contains numerous little seed-like bodies, adhering by one end around the sides of the central twig. These seeming seeds have a thin and tough hull, of a yellowish white color; they are egg-shaped, pointed at one end, and are nearly one eighth of an inch long. The gall-insects live singly, and undergo their transformations, within these seeds ; after which, in order to come out, they gnaw a small hole in the hull, and then easily work their way through the spongy ball wherein they are lodged. 

A Report on the Insects of Massachusetts, Injurious to Vegetation

Seminator Harris (autumnal). 

White oak

Well described and figured by Dr. Fitch, N. Y. Rep. II, § 315, except that, as noticed by Osten Sacken, {Proc. Ent. Soc. Philad. I, p. 69) the figure does not show the numerous “angular projections” which exist in nature. Rather rare near Bock Island, IL. 

Gall-fly, Cynips seminator Harris and O. S. I have not reared this but have received numerous specimens male and female from Mr. Bassett.

On Dimorphism in the Hymenopterous Genus Cynips: With an Appendix, Containing Hints for a New Classification of Cynipidae and a List of Cynipidae, Including Descriptions of Several New Species, Inhabiting the Oak-galls of Illinois

C seminator Harris

Harris. Insects etc. p. 548; Fitch. Rep. 11, No. 315; O. Sack.. Proc. etc. 1, 69, No. 21 ; Walsh. Proc. etc. II. p. 465 (at the top); (male female; Q. alba). 

I had expressed some doubts about the identity of the specimens obtained by me from these galls, with those described by Fitch, as he says that the thorax of the female is cinnamon-red. Mr. Walsh confirmed my doubts, venturing even the supposition that the gall-fly described by Fitch was a guest-gall-fly. I believe now to have found the solution of the difficulty. Having examined my specimens recently, after a lapse of several years, I find that the thorax of all the female specimens has become reddish, whereas that of the male specimens has remained black. It seems probable, therefore, that Dr. Fitch had rather old specimens before him when drawing his description. C. seminator belongs to the genus Andricus Hartig.

Contributions to the Natural History of the CYNIPIDAE of the United States and of their Galls. Article 4th. 

Callirhytis seminator

The three "Willow galls produced by Sawflies, that we have already treated of in this Article, are all " monothalamous." The two Oak-galls that we are now about to describe are both of them " polythalamous " or many-celled; that is, each gall contains an indefinite number of distinct cells, each of which is inhabited by a single gall-making larva. In the "Wool-sower gall (Fig. 45 a, sectional view), these cells may be seen in the middle of the gall, and are little pip-like bodies having much the appearance of a canary-seed, one of which we represent enlarged at b, so as to show the hole through which the perfect fly has made its exit. The reader can form a tolerably good idea of the shape and make of this fly, by referring to the drawing given in our first "Volume (page 104, fig. 81) of an allied gall-fly, which however is thrice as large and which differs further from the Wool-sower Gall-fly by the wings being much marked with brown-black. 

The Wool-sower gall is met with exclusively on the "White Oak, and like the Oak-fig Gall to which we formerly referred (Vol. I. p. 101) is, not a bud-gall, but a true twig-gall, growing early in the spring out of the bark of the twig itself. Mr. Bassett (Proc. Ent. Soc. Phil., 11, p. 331) broaches the theory that the Wool-sower gall and Osten Sacken's Q. operator gall are not twig-galls, but true bud-galls, and that "their cells are modified leaves, the silky fibres covering them being only a monstrous development of the pubescence always observable on young leaves." But 1st: As to the Oak-fig gall, we have already recorded the fact that "this mass of subglobular galls about the size of peas is clustered densely around the infested twig, without in any wise interfering with the normal development of the buds." {Ibid. VI. p. 275.) We may remark by the way that we have recently found the Oak-fig gall upon un- doubted Bur Oak {Q. macrocarpa), although it had been previously supposed that it never occurred except on White Oak (Q. alba). 2d: As to the Q. operator gall, we ascertained long ago that it is a deformation, not of the twig, nor of the leaf-buds, but of the male flower of the species of Oak, upon which alone we have hitherto met with it, namely the Black Oak (Q. tinctoria); for the Black-jack Oak (Q. nigra), upon which Osten Sacken first discovered it, does not grow in North Illinois. Even on this last oak Osten Sacken records the fact that his gall occurred exclusively ''on young flowering branches. (Ibid. I. p. 266). 3d: As to our "Wool-sower gall, if the cells were a deformation of the buds, we should surely find them gathered into two distinct groups around the bud on each side of the oak- twig that gave origin to them, as in the gall which is next to be noticed; whereas they are always evenly distributed around the axis of the twig. Besides the pip-like cells to which we have already referred, it is composed of little else but a mass of whitish, spongy wooly matter, the external surface of which is of a pretty rose-color early in the season, but towards the middle of the summer assumes a rusty brown shade. At every period of the year the outside of the gall is invariably studded with numerous conical projections or teeth, which are very characteristic, though our engraving scarcely shows them as pointed as they arc in nature, and Dr. Fitch's figure omits them entirely. The perfect Gall-fly comes forth about the end of July, and the female must then, after coupling with the males, puncture such White-oak twigs as she judges to be suitable for her purpose in a very great number of adjoining points, dropping an egg along with a minute drop of poison into each puncture. Until the following spring these eggs always lie dormant, as in many other such cases; for Dr. Fitch is altogether wrong in asserting that there are two distinct broods of Wool-sower Gall-flies every year, generating two distinct sets of galls.* We have examined hundreds of these galls at all seasons of the year; and never yet did we find one at a later period than the end of July, that was not bored up, empty and untenanted. In fact, it is not often that they remain on the twigs through the winter; for when ripe they are attached so very slightly to the twig upon which they grow, that they can readily be slipped up and down like the beads of a rosary, and the least lateral jerk displaces them entirely. 

Callirhytis seminator

This species, before only recorded as occurring on the white oak (Quercus alba), is not unconnnon here, both on Quercus prinus and on the swamp white oak Quercus bicolor. Callirhytis operator O. S., occurring on the black-jack ( Q. nigra) may be a phytophagic variety of this well known specie ; the galls are similar, but the flies are certainly distinct. I have both species in my collection. Calllrhytis seminator begins to develop here, on the small twigs, in April ; by the middle of June the flies are fully developed, but they do not escape from the galls until the first week in July. 

On The Cynipidous Galls of Florida

Andricus (Callirhytis) seminator

The gall of this species is a brown woolly mass from one to two inches in diameter and enclosing a large number of seed-like bodies each one of which contains an insect. Always occurring on the twigs of Q alba. Iowa, MI, FL. Eastern US.

The Gall-producing Cynipidae of Iowa

Callirhytis seminator

Cynips seminator
Andricus seminator

These small seed-like monothalamous galls are massed together on the twig and covered with fibers forming a mass 15-45 mm in diameter. White dotted with red when young, turning brown in the fall. On white oak, Quercus alba. Common. Insect in early Summer.

Insect galls of Springfield, Massachusetts, and vicinity

On Callirhytis seminator. (Cynipoidea, Hym,). 

This beautiful gall is common in the vicinity of Blacksburg, Virginia, on white oak. A number of them were collected on June 24, 1903: at that date their age varied, but adults were emerging from the mature galls. The young galls consist of a radiating mass of larval cases on a common receptacle at the end of a twig at the base of a leaf petiole. Each larval case is surmounted by a glossy white substance resembling glass wool, and which by combination with that of adjoining cases forms a complete, globular and more or less compact woolly ball. As the galls increase in size and approach maturity, the larval cases lengthen from their distal end and push the woolly substance out into point-like protuberances. The galls turn brown when maturing. They may also be found along the side of a twig, in one case the receptacle being formed on a developing bud. The eggs of this cynipid are probably deposited within a bud. The galls are large and conspicuous, flower-like at times and bitter to the taste. There are commonly two receptacles, side by side, in the place of the two apical buds of the twig. 

The young larval cases are seedlike and measure about three millimetres; they taper at the distal end and each bears a tuft of woolly substance. In the mature galls each case has become elongated into fleshy spokes, green and herbaceous, which measure about thirteen mm. in length, about half of which is the elongated distal end. 

The adults issue through large holes at one side of the distal extremity of the larval case (the basal, swollen, seed- like portion of it) and tunnel their way through the surrounding substance to the open air, leaving for the time being a small shotlike hole; these soon close up owing to the nature of the gall substance. The adults emerge for a period of at least two weeks. The gall also occurs at Cumberland, Maryland. 

Parasites are numerous; a golden-haired Eurytomid was reared from the Virginia specimens. 

Fragments on North American insects II

Callirhytis seminator

Quercus alba

Gall appears early July, plate 2, 8. Flies the last of June.

Callirhytis seminator

In MD and VA:

By June 7, 1901, pupae were present in the galls of this species at Annapolis, emergence following about one week later. On June 16, the same year at Blacksburg, Virginia, adults were emerging, continuing up to July 3. 

Fragments on North American insects IX

Callirhytis seminator

white or pinkish, woolly

CALLIRHYTIS SEMINATOR (Harris) 

Galls of this species are here recorded on Quercus alba from the following localities: Williams Bay, Wis.; Fort Sheridan, Glencoe, Evanston, La (grange, Glen Ellyn, Willow Springs, Kankakee, and Utica (Starved Rock Park), IL.; Cedar Rapids (Scott), Iowa: Miller and Porter, Ind. ; Poplar Bluff, Mo.; Texarkana, Ark.; Tuskahoma, Okla. ; Troy, Ala. ; Fairfax, S. C. ; Richmond, Rosslyn, Alexandria, and Bedford County (Apple Orchard Camp), Va. ; Plummer Island (McAtee), Md. ; Gettysburg, Pa.; Ithaca, Industry (Crosby), East Hampton (Crosby), and Farmingdale (Crosby), N. y. At Evanston the galls were found just starting on May 17 and adults issued June 29-July 12. At Washington the galls start to develop early in April. Middleton reared adults at Falls Church, Va., June 13, 1913, June 13, 1911, and June 18-29, 1915. Galls from Kanawha Station, W. Va., collected by Hopkins gave adults June 21-25, 1912. The writer has seen the gall on the rock chestnut oak, Q. montana, at Falls Church, Va., and on the basket oak, Q. prinus, at Gainesville and Jacksonville, Fla., the latter host being previously unrecorded for this species, 

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

Callirhytis seminator

A globular or elongated woolly or spongy white mass often tinged with spots of pink, 20-30 mm. in diameter, consisting of numerous slender fusiform bodies attached by one end to a common point on the twig —probably a bud gall morphologically. Each seed-like body contains one larval cell and the distal part bears the white filaments. Occurs on trees of Q. alba, starting about the middle of May, the adults emerging June 29-July 12. 

Cynipid Galls of the Chicago Area

WOOL SOWER GALL Callirhytis seminator (Harr.) 

The wool sower is composed of a large number of small hairy galls attached to a common point on twigs of the white oak, Quercus alha, thus forming a compact woolly mass. [Subfigure] A represents a single gall. 

Color: white, often tinged red, turning brown. 

Callirhytis seminator

Quercus alba, michauxii
Stem galls, detachable
Oak Seed Gall. Wool Sower. Globular, 20 mm in dia, white with pink spots. May. Many-celled.

Quercus prinus [montana]
Stem galls, detachable
Oak Seed Gall. Wool Sower. Globular, 20 mm in dia, white with pink spots at apex of seed-like bodies, in May-June.

[Photo caption]
137. On Q alba. Oak Seed Gall. Also on Q michauxii, prinus [montana]. Adults emerge in late June after which the gall dries up.

165. On Q alba, Fune Park IN. June 18 on same tree with the oak seed gall, Callirhytis seminator. Adults (all males emerged July 2-12. Interpreted as an abnormal specimen of that species.

Callirhytis seminator

Quercus alba

A showy and attractive gall growth on oak twigs. The large number of small, hairy galls are attached to a common point to form this pinkish-white, wooly growth. A gall with a similar appearance may be found on several other species of oak. The Wool Sower was called by E. P. Felt ". . . one of the finest of natural objects." 

[photograph included]

Some plant galls of Illinois

Weld lists this species as a stem gall, and this is how it is typically perceived, but observations made early enough in spring will show that it is in fact a bud gall. This is why it is most often found at the terminus of twigs. Galls found elsewhere on the stem emerge from lateral buds.

Callirhytis seminator is most frequently confused with Callirhytis quercusoperator, a catkin gall on red-group oaks. Aside from the absence of catkins and host ID, Callirhytis seminator can be distinguished by its regular pink-turning-brown spots and more regularly sphere-like shape. 

It may also be confused with Andricus aciculatus, a stem gall on Quercus stellata. Andricus aciculatus has much denser wool, often condensing to a near-impenetrable felt when wetted, and lacks pink or brown spots entirely. 