Disholcaspis quercusmamma (agamic)

Amphibolips quercusspongifica (sexgen)

Amphibolips confluenta

Callirhytis seminator (sexgen)

Ampelomyia vitispomum

Ampelomyia vitiscoryloides

Antistrophus pisum

Cynips quercus mamma [new species proposed but not thoroughly described]

[footnote]

See Proc Ent Soc Phil III, p 639, note. The gall resembling the oak-bullet gall (Q globulus Fitch) which is there mentioned as occurring on Burr oak, has been since ascertained by us to be produced by a distinct species of Gall-fly from that which produces the oak-bullet gall. The gall itself has the same very remarkable internal structure, but differs externally in being somewhat rougher and in usually having a little nipple at its tip, whence we may call it the oak-nipple gall (Q mamma). The fly, like that of the oak-bullet gall, occurs only in the female sex. Thirty-eight specimens, all females, came out from galls of the same year's growth Oct 22 to Nov 7. It may be called Cynips q. mamma, as it is an undescribed species.

The True Oak Apple as it is popularly termed, (Quercus spongifica, Osten Sacken, occurs exclusively upon the Black oak (Quercus tinctoria [velutina]). It commences its growth in May, or as soon as the young leaves put forth, and reaches its full size in a few weeks. The central cell in which the larva resides becomes eventually hard and woody, but the space between that cell and the external skin or rind of the gall is always completely tilled by soft, drab, spongy matter. By the forepart or middle of June both male and female gall-flies (Cynips quercus spongifica OS) eat their way out of a certain number — say about a fourth part— of these galls, having developed into the winged state from the larva in the central cell. The hole by which the fly makes its exit is shown at Fig. 78 b. The remaining larvae lie dormant for more than two months, when they change into the pupa state, and subsequently about October eat their way out in the form of gall-flies (Cynips q aciculala, O. S.) closely allied to and yet quite distinct from those produced in June. Out of thousands of these autumnal flies examined by us, all were females with not a single male among them; and we have experimentally ascertained, by colonizing a number of these females upon isolated black oaks known to be not previously infested with oak-apples, that they cause oak-apples to be generated in the following spring upon such isolated Black Oaks. From Oak-apples produced in this manner we have bred two specimens of the spring form of Gall-fly (q. spongifica) which exists in both sexes, and five specimens of the autumnal form (q. aciculata) which exists exclusively in the female sex. Finally, treating these five autumnal specimens in the same manner, i. e. placing them upon another isolated Black Oak, we obtained galls in the following spring which produced two specimens of the spring form (spongifica), thus showing that the autumnal form sooner or later reverts to the spring form. Hence, as well as from other considerations, we may infer that the former is not a distinct species but a mere "dimorphous" female form of the latter; for otherwise, one form could not generate the other form. 

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. 

Cecidomyia Vitis pomum, new species

For the satisfaction of the scientific reader, we annex descriptions of the above gall and of its Iarva, drawn up from the Alton specimen. 

Gall Vitis pomum.— A smooth, globular, fleshy, grass-green gall, 0.9 inch in diameter, attached by a rough base of about 0.4 inch in diameter, like the base of a hazelnut, to the cane of the grapevine. Its external surface with about eight or nine longitudinal striae, dividing it into eight or nine segments, like those of a watermelon. Internally fleshy and of the consistence of the hull of a walnut for one-eighth of its diameter; then a series of elongated cells, divided each into two cells by a regular series of transverse partitions, the lower tier about 0.2 inch, the upper tier about 0.3 inch long. From center of one cell to that of the adjoining cell is nearly 0.1 inch, and there are seven or eight cells side by side.

In No. 2, page 28, and No. 3, page 54, of the American Entomologist, we referred to a "vegetable phenom- enon" said to be found in Virginia, in the form of an apple-like growth from a grape-vine. The prevailing opinion in that State seemed to be, that it was a kind of hybrid fruit formed by the union of a grape blossom with an apple blossom. But we intimated our opinion at the time, that it was no fruit at ail, but simply a gall produced by some unknown species of gall gnat. We have since received specimens of what is uudoubtedly the same tiling, from two different sources, first from Mr. B. L. Kingsbury of Alton, Illinois, and second through the kindness of Mr. Stauffer, of Pennsylvania, from Thos. Moehan, the well known editor of the Gardeners' Monthly. Mr. Stauffer has also favored us with a good colored figure of one that he cut from the wild Frost Grape (Vitis cordifolia), August 9th, 1850, which agrees perfectly well with the two specimens in our pos- session. Hence, after carefully examining these specimens, we can now announce with certainty that this ''vegetable phenomenon"' is really what wo originally inferred it to be — namely, a gall- niadc by a gall gnat. Fig. 85 a, will give the reader a very good idea of this gall, and Fig. 85, b, of its internal structure, showing the larvae that inhabit its numerous cells, a single larva in a single cell. All the galls that we have hitherto been treating of, have been what are technically termed "monothalamous" or "one-celled" galls, inhabited by a single gall-making larva. But this, as will be seen at once, is a "polythalamous" or many-celled gall, inhabited by a great number of gall-making larvae. 

As the fly that generates this gall will, in all probability, not make its appearance until next spring or summer, and as we have consequently had, as yet, no opportunity to breed it; it may be very reasonably asked, how we know for certain that it will turn out to be some kind of Gall- gnat ( Cecidomyia)? We answer that the larvae of all Gall-gnats are distinguishable at once from other larva? by a peculiar process known as the "breast-bone," and located on the lower surface of the first joint of the breast. (See Fig. 86, c.) Usually this "breast-bone" is of so dark a color that it can be readily seen, even in a very small larva, and its use apparently is to abrade the surface upon which the larva lives and there- by cause an abnormal flow of sap, which forms the food of the little insect that is thus working for its living. In Figure 8G, c, the head of the lar- va is shown protruded ; but all this group of larvae have the power of retracting the head within the body, so as to bring the "breast-bone" well into play. In shape, this organ differs greatly, being sometimes what we have called "clove-shaped," as in Fig. 86, c, sometimes Y-shaped, as with the larvae of the two Willow-galls figured above, and sometimes of other allied shapes. But in every case there are several sharp prongs in front. of it, adapted for wounding and piercing. As a general rule, allied gall-gnats inhabiting the same genus of plants have larvae with "breast- bones" of the same, or a very similar shape. For example, that of the larva to be next described is absolutely undistinguishable from that of our larva; and so is that of Ihe larva of the Pine-cone gall from that of the larva of the Cabbage-sprout gall.

Cecidomyia Vitis coryloides, new species

Gall Vitis coryloides, n. sp. On the vine of Vitis cordifolia [vulpina] — A roundish mass, 1.25 to 2.5 inches in diameter, of from 10 to 50 opaque, woolv-pubescent, fusiform, or sometimes flattish-oval, green galls, each from 0.59 to 0.75 inch long, the whole springing from the point where normally a bud would be located. Generally it is only the terminal half of each gall that is pubescent, the basal half being smooth. The interior of each gall is fleshy, juicy and subacid, with a single longitudinally central cell 0.25 inch long and 0.06 inch in diameter.

We have met with one or two small specimens of this gall growing upon the cane of the wild Frost Grape in Illinois; and we were presented with two very large specimens by Mr. Mills of Hock Island, IL., which had grown upon a Frost Grape planted in his dooryard, from one of which the annexed drawing is copied (Fig. 80). The whole mass of galls springs from a common centre at the point where a bud would normally be, and is evidently a mere deformation of a bud. Occasionally an undeformed leaf with its peduncle still entire puts forth from the common centre, sometimes bearing a couple of galls at the junction of the peduncle with the leaf. each gall is one-celled, the cell being about a quarter of an inch long and one-fourth as wide as long, and containing a single larva. (See Fig. 86,b). The larva closely resembles that of the Grape-vine Apple-gall, and is therefore no doubt that of some Gall-gnat. Large sized specimens of this gall bear a general resemblance to a bunch of filbert or hazel nuts, as they grow on the bush: hence the name that we have given it. Fuller details will be found in the foot-note.

Lygodesmiae pisum, new species

There is a rush-like plant about a foot high, with slender sprangling stems and a few rigid lance-shaped leaves, which inhabits Nebraska and the regions to the east and north of that territory, and is known to botanists as Lygodesmia juncea. On the stems of this plant there often grows a profusion of round or oval pea- like galls, ranging in diameter from 1/4 to 1/2 an inch, such as are represented in the annexed Figure 47. In the autumn each of these galls contains, in a central cavity about one-tenth of an inch in diameter, a fat yellow legless maggot, with a large round head and robust jaws tipped with black. Except the central cell, the rest of the gall consists of a dense whitish spongy matter, which ultimately becomes so hard as to be penetrated with some difticulty by the thumb-nail. About the middle of the following May there eats its way out of the gall, through a small pin-hole (Fig. 47, a), a black Gall-fly about one-eighth of an inch long, which scarcely differs in general appearance from the Oak-plum Gall fly (Vol. I. p. 104, Fig. 81) except in being so much smaller and in lacking the dark shade on the front wings. This Gall-fly is entirely new to science, and, as we have already explained, it is especially interesting because — growing as it does on a group of plants not hitherto known to be infested by Gall-flies — it presents structural characters different from those found in any other Gall-fly. In other words, a new genus has to be established to receive it, besides giving the characters separating it from any other species belonging to the same genus, which may hereafter be discovered. But as such details as these are only of interest to the scientific reader, we shall throw them into the form of an Appendix — to be "skipped " at discretion by the general reader.

Galls and their architects