S siliqua n. sp.?=Salicis? Fitch=rigidae? Fitch, OS

On S humilis (and also on S cordata? and S discolor?)

A monothalamous, solitary, oval or subspherical. woody gall, .55 — 1.00 inch long and .20 — ..34 inch in diame- ter, growing at the tip of a twig, frequently with several twigs apparently of the same year's growth surrounding it, tt pared at tip to a short, blunt, tubiliform beak, which is evidently a deformation of the terminal bud, and hollow inside. The outside surface of the gall, which is the natural color and texture of the bark of the twig, always contains, besides the terminal beak-like bud, 2 — 5 buds, which are still alive in November in the recent gall but afterwards perish along with the gall itself, as does also, unless the twig on which the gall grows be large, a portion of that twig. Sometimes one of these external buds sprouts out into a twig, growing from the outer surface of the gall, and in a single spe- cimen there are four such twigs. The walls of the internal cell or hollow, in- cluding the bark, are .06 — .11 inch thick, and lined when mature inside with the cocoon of the gall-maker, which is detached and of the usual delicate texture towards the tip of the hollow, so as to form a kind of diaphragm to exclude any air that might enter through the terminal beak, but is agglutinated strongly to them everywhere else, though it may be detached piece-meal, generally with a thin layer of the greenish woody matter adhering to it. The internal surface of the terminal beak is smooth, continuous with that of the main c. 11 or hollow, and not strongly pubescent at tip as in <S'. cornu ; on its external surface there is the natural suture at its base. In one specimen, where a large, abnormal, woody wart had been formed about the middle of the hollow, the larva, instead of including the wart in his cocoon, had had the remarkable foresight to con- struct his cocoon entirely above the wart, and was thus compelled to make another diaphragm just above the wart, besides the usual one near the beak, and to lie in a much smaller compass than usual between the two. Described from 10 living- specimens and 27 old and dead ones, all from S. humilis. Rather rare near Rock Island. Varieties of S. ha- tatas n. sp. occur, which externally can scarcely be distinguished from «S'. siliqua ; but on cutting into them they are seen to be not hollow, but filled with a spongy substance containing several of the cells which are inhabited by the Cecidomyia of that polythalamous (xall; and more- over, the terminal bud is not beak-like and tubiliform. Specimens found on S. cordata in November differ as follows: — \st. The average dimensions are about i smaller, the length in 4 living spe- cimens and 41 dry and dead ones being .45 — .85 inch and the breadth .17 — .28 inch. 'Ind. Out of three of the living galls where the Ceci- domipa was present, there was in two a double diaphragm both at top and bottom of the hollow, instead of the single diaphragm at the top only; but in the other one the diaphragm was single and normal, 'ird. The number of buds on the external surface of the 45 galls is 1 — 3 in- stead of 2 — 5. \t]i. The terminal beak in i of the above 45 specimens is conspicuously recurved, whereas it is never recurved in those that grow on 8. humilis, thovigh it is sometimes a little oblique and in a single specimen is at right angles to the axis of the gall. A gall found August 1 had the beak so much recurved as to touch the side of it, like the tongue-case of the pupa of vSphinx 5-maculata Haw. — From my having in two successive seasons found the old dead and dry galls on both the above two willows at least 8 or 10 times as numerous as the green ones, and from the very weather-worn appearance of many of them, and the fact that a few of them were overgrown and almost obli- terated by the twigs that surrounded their base, I infer that they hang on the twig for several years. A single living gall gathered on S. discolor in November differed from the living ones found on S. humilis as follows: — Is^. The woody matter composing the outer shell is much thinner than in any one of 14 green specimens off S. humilis and 3 green specimens off S. cordata that I have cut into, being to a much greater extent medially interrupted by a layer of brown spongy matter, so that the gall was rather crushed by the knife than cut by it. 2.nd. Instead of the external surface being phimp and of the natural texture of the bark of the twig, it was strongly rugose, when recently gathered, and had much the color and texture of a completely withered blue plum. This does not occur in green specimens found at the same time of the year on the other two Willows, though it is often seen in the old dry ones. — Length 1.00 inch, diameter .80 inch, external buds 3. One specimen.

- BD Walsh: (1864) On the Insects, Coleopterous, Hymenopterous & Dipterous: Inhabiting the Galls of Certain Species of Willow. Pt 1st--Diptera^©

Reference: https://www.biodiversitylibrary.org/item/23810#page/611/mode/1up