Andricus quercusstrobilanus (agamic)

Andricus lustrans (agamic)

Amphibolips quercusspongifica (sexgen)

Amphibolips confluenta (agamic)

Amphibolips quercusinanis (sexgen)

Callirhytis quercuscornigera (agamic)

Amphibolips quercusjuglans (agamic)

Cynips quercus strobilana, n. sp. (as yet not reared)

On Quercus prinos, var bicolor [Quercus bicolor]. Large gall, at the tip of twigs, consisting of a number of wedge-shaped bodies, fastened by their poitned ends to a common centre. Diameter about an inch and a half. C q. stobilana [sic] (as yet not reared)

These specimens measure rather more than an inch and a half in diameter and look somewhat like the cones of some kinds of pine, for instance, of the scrub-pine, as they consist of a number from 20 to 25 or more of wedge-shaped bodies, closely packed together, with their pointed ends attached to a common centre. These wedges are hard and corky and break off very easily when the gall is dry. Each of them contains a hollow kernel with a plump, large larva inside. This gall is evidently produced by the sting of the insect on the single leaves of a bud, each leaf growing into the shape of a wedge.

[unnamed]

Quercus obtusiloba. Post oak. 

Clusters of small, somewhat bell-shaped, petiolate, greenish galls on the under side of the leaves, along the midrib.

Their shape may be compared to that of the flowers of Vaccinium. They are attenuated at the basis into a short petiole, fastened to the midrib of the leaf; the opposite end is truncated the truncature being excavated; the length, from the foot of the petiole to the truncated end, is from 0.12 to 0.15 inch. They grow in numbers, sometimes of ten or more together, so that six, for instance, form a row on one side of the midrib and four or five on the opposite. When found by me on the tree in October, 1861, these galls were pale green; the dry specimens are brownish. Inside of each was a small whitish larva, probably of a Cynips. 

Cynips quercus coccineae

Quercus coccinea. Scarlet oak. Large, more or less round gall, not attenuated at the basis, surface glossy, shell thin and brittle; on the inside with a spongy substance, surrounding a kernel in the centre. Diameter upwards to an inch and a half. 

The external appearance of this gall is very like that of the gall of C. q. inanis. It is more or less globular (although irregular specimens of both frequently occur), that is, not narrowed towards the basis; its surface is glossy. Internally, it is easily distinguished by the spongy mass which fills it. It seems to reach a larger size than the former gall, as among six specimens now before me, one measures an inch and a half in diameter and two others are but little smaller, whereas among eight specimens of the gall of C q inanis the largest does not much exceed an inch. 

From the following gall [Cynips quercus spongifica] it is distinguished by its glossy surface, its less dense and more whitish spongy internal matter, its much thinner and brittle shell and by its shape, which is more rounded on the top. 

Cynips quercus spongifica

Quercus tinctoria [velutina]. Black Oak. Large, round gall, somewhat attenuated and pointed at the top; surface more or less opaque, as if powdered or dusted; shell thick, inside, a dense, spongy, brownish substance, surrounding the kernel. Diameter about an inch and a half.

This is the opaque variety mentioned [in "On the Cynipidae of the North American Oaks"] under the head of Cynips confluens. On the 25th of May last I found four full-grown specimens of this gall on the leaves of a large black oak and have obtained, on June 15, three female specimens of the gall-fly. They look exactly like C. q. inanis, only they are a little larger (the gall also being larger). 

Of these galls three, taken from a high branch of the tree, can be considered as typical specimens. They are slightly oblong, that is, somewhat extended into a point at the end, although not narrowed at the basis. Their diameter is about an inch and a half. Their color is drab, sometimes spotted with brown on one side; the surface is more or less opaque, as if powdered or sericeous, and shows very little gloss. The shell is much thicker than that of the two previous species [Cynips quercus coccineae and Cynips quercus inanis]; the spongy mass is more dense and brownish.

A fourth specimen, found on the same tree, is more irregular in its shape; its surface is without any gloss and altogether drab, without brown spots. Specimens of this kind are frequently found on young shrubs of Q tinctoria [velutina], the leaves of which are very rusty-puberelent beneath.

Cynips quercus aciculata 

Quercus tinctoria [velutina]. Black Oak. Large, round gall, broad and rounded at the top; surface smooth and glossy; shell thick, inside, a dense, brown, spongy substance, surrounding the kernel. Diameter upwards to an inch and a half. 

The specimens can be distinguished at once from the gall of C q spongifica, by their smooth, glossy surface and their subglobular or short-oval form, their basis being slightly attenuated, their top, on the contrary, being broad and rounded. Otherwise, their thick shell and their dense, brownish spongy substance reminds of C q spongifica. 

Mr. Walsh noticed their appearance in summer (about July). The gall-flies usually remain in the gall through the winter and escape in the spring; sometimes, however, especially when the weather in the fall is unusually warm, the flies leave the gall already at that season.

The synonymy of this species with C confluens Harris, supposed by Mr Walsh, is founded on the occurrence of their galls at the same season, and on the statement of Mr Norton about the agreement of C q aciculata with the original specimens of C confluens in Dr Harris' collection. But if Dr Harris' gall-fly really lives on the red-oak (Q rubra),  its great resemblance to C. q. aciciculata, occurring on the black oak (Q. tinctoria [velutina]) would no more be a proof of their identity, than the great resemblance of C. q. inanis and spongifica is of theirs. The two latter gall-flies, although almost perfectly similar in appearance, occur on different oaks and produce quite different galls. It may be that the true C confluens Harris, although closely resembling C. q. aciculata, produces on the red oak a gall, sufficiently different from that of the other species, to be distinguished by constant characters. The synonymy of both therefore, although probable, seems to require further confirmation.

It is also worthy of remark that both species of one group (C. q. aciculata and centricola) are produced by autumnal galls, and escape either late in the fall, or remain in the gall through the winter, whereas, the species of the other group all belong to vernal galls, the gall growing with the leaves and the fly passing through all the stages of its growth between the earliest spring and the end of June.

Cynips quercus inanis

Q coccinea. Scarlet oak? Large, more or less round gall, not attenuated towards the basis; surface glossy; shell thin and brittle; on the inside whitish filaments radiating from the kernel to the shell. Diameter about an inch. 

I have found this gall more than once on young trees, belonging either to Q coccinea or Q rubra. (the leaves were elongate, cuneate at the basis and hardly or, at least, not deeply, sinuate; this is, I believe, one of the varieties of the scarlet oak.)

Among the specimens of my collection, I find a number of galls, collected in one locality and somewhat different in shape from the typical specimens of C q inanis. The latter are more or less globular, the leaf being, so to say, the tangent of the globe. There is no distinct point or nipple on the top. The other gall, on the contrary, is somewhat lemon-shaped, being attenuated at its basis with a corresponding elongation, ending in a minute nipple, at the opposite end. Its color is more brownish than that of C q inanis; on the inside, I did not detect any difference between both galls. The tree is also either the red or the scarlet oak.

Cynips quercus cornigera n. sp. (as yet unknown) [ie gall named without an adult wasp specimen]

Quercus palustris Pin oak. 

Woody knots on the limbs, emitting pale yellow, conical, brittle projections. 

Of all excrescences on oaks in general, the present one, wherever it occurs, is perhaps the most conspicuous, as by its abundance it deforms the tree and seems to cause considerable injury. It consists of woody knots on the limbs, looking usually as if many of them were closely packed together and thus forming an oblong, woody irregular mass, sometimes two inches or more long. Its most striking character are its slightly curved conical projections, hollow on the inside, which bud forth from all sides of the gall. On dry, dead galls, these horn shaped projections are for the most part broken off, so that their bases alone are visible, projecting like short tubes from the cracks of the woody tubercle. 

After having very frequently observed dead galls of this kind, I finally succeeded on the 13th of May, 1862, to find some young and growing ones. They were of moderate size; their back was greenish and their wood soft and succulent. The conical projections were just beginning to bud forth; when laid bare, by removing with a knife the wood around them, they appeared to extend deep inside of the gall, almost down to the twig. Their color was whitish, their consistency soft, apparently fibrous, and not woody. At that time, they were not hollow yet, and I could not find any larvae in them. When I visited the same spot during the latter part of June, I found some of the horn-shaped bodies already projecting about one-tenth of an inch; their substance had become harder and more woody; their inner end had become club-shaped, distinctly isolated from the surrounding wood, so that the whole of these bodies could be easily removed by cutting away the wood around them. On the inside, the inner end was hollow and contained a small larva. 

Cynips quercus juglans n. sp. [gall only]

QUERCUS ALBA. White Oak? Large, round gall of a hard corky substance, growing on the branches; a round, hollow space in the center. Diameter 0.75-0.95. 

I found a couple of these galls in winter, on the ground, under an oak, the species of which I was unable to ascertain. Afterwards, Mr. Hitz, of the Maryland Agricultural College, communicated to me a number of these galls, with the statement that they grow on the branches of the white oak. All these galls, as well as those found by myself, were somewhat shrunken and wrinkled on the surface, probably from the effects of dryness. They are easily distinguished from the galls of C q. globulus Fitch by their large size and their much harder substance. It requires some effort to cut them open, whereas, the dry galls of C. q. globulus can be easily cracked. For the same reason the kernel of the latter gall can be more easily detached from the surrounding corky substance, than that of the other gall. The greater part of the galls which I cut open contained a cluster of small evidently parasitical larvae. In two or three, however, I found a single Cynipideous larva. I did not succeed in rearing it, but obtained several kinds of parasites.

Additions and corrections to the paper entitled "On the Cynipidae of the North American Oaks and their Galls"