Rabdophaga strobiloides

Detachable: integral
Color: gray, white, green
Texture: pubescent, leafy
Abdundance: abundant
Shape: conical
Season: Summer, Spring
Alignment: integral
Location: bud
Form: abrupt swelling
Possible Range:i
Common Name(s):
Cecidomyia salicis strobiloides
Cecidomyia salicisstrobiloides
Cecidomyia strobiloides
Rhabdophaga strobiloides
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  • image of Rabdophaga strobiloides

On the Insects, Coleopterous, Hymenopterous & Dipterous: Inhabiting the Galls of Certain Species of Willow. Pt 1st--Diptera

S. strobiloides O. S.

On S. cordata [eriocephala?].

A monothalamous gall like a pine-cone, always on the tips of twigs when young, but often with small shoots of the same year's growth surrounding it, porrect, .50 — .90 inch in its transverse diameter, and in stunted galls where the gall-maker has perished even as small as .20 inch in diameter, generally when viewed laterally with an ovate outline and the tip more or less truncate, occasionally subspherical. The leaves com- posing it are all sessile, closely appressed and imbricate, and all those on the outside are covered with a short, dense, glaucous-white pubescence on their entire exterior surface, and occasionally in a less degree on their interior surface, and are reddish-brown inside when mature, those on the inside of the gall becoming gradually smooth and reddish-brown on their exterior basal portion, and finally throughout. Towards the base of the gall the leaves are orbicular, the basal ones smaller; the next leaves are obovate and with their tips in a semicircle, and as they approach the tip of the gall oblanceolate, and in the inside linear-lanceolate and gradually smaller, slenderer and straighter, till they finally embrace the central cell containing the author of the gall. External leaves, except towards the tip of the gall, with a number of branching veins springing from their base, the midrib scarcely distinct from them by its supe- rior size and throwing out similar branches, all of them obvious on the internal face of the leaf and obsolete on its external face. The tip of the twig from which the leaves spring, both in this and the 4 following species, is constructed as in C s. brassicoides.

Described from 30 specimens. Very common and abundant in Rock Island County, Illinois, hundreds of them occurring on, a single bush. None of the leaves composing this gall are ever serrate, as in the willow on which it grows, but always entire. When young and immature, the galls are spherical and are enveloped in a dense mass of foliage, which gradually falls off towards the autumn, and by November the twigs on which they grow, if small, are already killed for an inch or two down- wards. Occasionally at the extreme tip of the gall the leaves open out a little, as in S. strobiliscus n. sp., but without projecting from the tip as in that species. Easily distinguished from that gall by the portion of each leaf which lies "to the weather," towards the base of the gall, not terminating in a rectangular point, but describing a circular arc. The leaves are also more densely pubescent, especially the portion that lies " to the weather." Appears early in the summer and is full-sized by the middle of July, at which time that which is reddish brown in the dry gall is greenish white. The pubescence on the leaves retains its glaucous-white color to the last, except where they are badly weather- beaten. On the same bush throughout the summer may be seen the old, dry, last year's galls, and the young growing galls of the current year. I have already referred to the Orchelimum eggs often found under the scales of this gall. In one gall examined this autumn I counted no fewer than 71 of these eggs. In September I detected a species of Xiphidium, which according to Mr. Uhler is undescribed, ovipositing in the pith at the tip of a broken stem of Goldenrod (Solidago). Probably Locusturiae Latr. (=Gryllidae Leach) do not so generally oviposit in the earth as authors have hitherto led us to believe.

- 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/600/mode/1up

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