S coryloides n. sp.

On S discolor?

A very large and loosely expanded, monothalamous gall, resembling at a distance a bunch of hazelnuts in their natural husks, growing singly at the tip of a twig without any shoots surrounding it. porrect, its general outline spherical, sometimes elongate-spherical or short-spherical, 1.76 — -2. .35 inch long and 1.95 — 4.10 inch in diameter. The leaves composing it are on the outside large in proportion to the size of the gall, so that some of the middle ones are occasionally two inches across, free from pubescence except sometimes on their external base, entire, with the normal midrib and branching side-veins distinct, and are all of them very much opened out and recurved, the basal ones the most so, so that the latter often touch with their tips the twig on which the gall grows. The basal leaves are orbicular-ovate or ovate, only slightly smaller than the middle ones ; the middle ones are ovate, and both basal and middle ones have their tips tapering regularly in an angle of about 80° — 90°, not taper-pointed in an angle of 70° — 80° as is generally the case in S. rhodoides ; and their base describes an angle of about 90°, instead of being squarely and widely truncate, as in S. rhodoides, and even on the extreme base of the gall generally has a short peduncle nearly 1/8 as long as the leaf itself, which in each successive leaf gradually becomes longer as the tip of the gall is approached, when it is about equal in length to the leaf, which has now become oblanceolate. On the inside, the leaves suddenly become straight, porrect, and very much smaller, and are elongate-linear with their tips tapered to a very acute point, closely appressed, and gradually smaller, till they finally embrace the lanceolate central cell. In the autumn the leaves of this gall are dark reddish-brown, externally with a slight whitish bloom; at other seasons it is unknown to me.

Described from 4 specimens. Very near S. rhodoides, which occurs on a totally different willow, but sufficiently distinguished by the characters specified in the description, as well as by its average size being just double. One of the above 4 galls had the heart eaten out by some lepidopterous larva; and adhering to the leaves of another was the pupal integument of a Lepidopteron, much larger than any of those commonly bred by me from the allied galls. All of them, as is very generally the case in this group of galls, had many of their leaves eaten into by Lepidoptera. and contained much Lepidopterous "frass" or excrement.

I know but three Willow-bushes near Rock Island which can be re- ferred to S. discolor. One of them, a $ . of which I forwarded to Mr. Bebb the inflorescence, was pronounced by him to be certainly S. discolor ; it was from this one that I obtained the galls, which for the present I refer to S. batatas and S. siliqua. Of the second, also a female, I forwarded nothing but the fruit, and Mr. Bebb referred it doubtingly to S. discolor, but thought it might possibly be S. eriocephala. I have carefully compared foliage, twig and bud in these two, and have little doubt they are identical. At all events their very robust, vigorous twigs, tinged with purple and covered with whitish pulveruiescence, so as strongly to recall those of many varieties of apple-tree, and the large buds which have commenced opening out even as early as the last of November, effectually distinguish both, even in the winter time, from the 4 other species of Willow found near Rock Island. The third bush was not discovered by me till the last of November, and agrees so perfectly in all the above characters with the one which is undoubtedly S. discolor, as well as in the foliage, some of which still adhered to its twigs, that I have little hesitation in referring it to the same species. I observed however on its main limbs large blotches or wide bands of whitish-gray, which could not be seen on either of the other bushes. In any case the inflorescence next spring will definitively decide the question of its specific identity with S. discolor. It was on this last that I found the galls C. coryloides ; the second bush bore no galls at all.

S coryloides

I have since fouod two additional specimens in a different locality, and as before on S. discolor. Thus, in addition to the occurrence of two very distinct but closely allied bud-galls on the same species of Willow, S. humilis, viz : .S. rhodoides and S. gnaphalioides, we find two very distinct but closely allied bud-galls on the same species of Willow, S. discolor, viz : S. strobiliscus and S. coryloides.

Rabdophaga saliciscoryloides

Host: Salix ?discolor

Salix
Bud gall comprising many modified leaves
Leaves loose, exfoliate, forming an open rosette
Leaves almost as wide as long
Galls leaves open, flared, the gall shorter than wide

[A drawing of this gall appears on page 277, Figure 412]

Galls are 5-7 cm long and 5-10 cm in diameter. The difference between these and galls of R. salicisbrassicoides and R. salicisrhodoides may be only superficial.

Range: IL

[Note referring to this and several other bud gallers]: Leaves of these galls are typically largest on the outside of the gall but narrow considerably toward the center of the gall. In this key only the outer leaf shape of the mature gall is described. The gall formers are always at the heart of the gall, surrounded by linear leaves. The larva feeds upside down and reverses position before pupation. The gall makers have one generation per year, are full grown in fall, overwinter in the gall in a cocoon, and pupate the following spring. Infested twigs are considerably stunted.