Cynips heldae (agamic)

Family: Cynipidae | Genus: Cynips
Detachable: detachable
Color: brown, gray, pink, red
Texture: bumpy, hairy, hairless, mealy
Abundance: occasional
Shape: globular
Season: Fall
Related:
Alignment: erect
Walls: thick
Location: bud, petiole, upper leaf, lower leaf, leaf midrib, on leaf veins, stem
Form:
Cells:
Possible Range:i
Common Name(s): Thorny Gall Wasp
Synonymy:
Pending...
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image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)
image of Cynips heldae (agamic)

The Gall Wasp Genus Cynips

Cynips multipuncatata var heldae
agamic form

The agamic galls of all of the species of the genus are produced on the veins of the leaves of white oak, with the single exception of Cynips heldae, which occurs either on leaf veins, petioles, or young stems of the oak.

GALL:
Generally spherical (as seen in cross-section), but so distorted with peculiarly irregular ridges and spines on the surface as to appear very irregular, even cubical; up to 10.0 mm. in diameter, completely covered with an irregular, often twisted mass of broad, blunt spines which are usually flattened and often ridged; the surface of the gall smooth, naked, with a microscopic scurf on the younger galls, this scurf more or less lost on the older galls; young (but fully grown) galls light reddish-brown in color, often lighter gray because of the scurf, the older galls dark, dirty brown. Internally solid with a compact, crystalline substance which is not as hard as in Cynips echinus and which contains more compacted, branched fibers; the larval cell large, up to 4.0 mm. in diameter, central or asymmetrically placed. Occurring singly or in compacted, distorted masses of as many as 8 galls, on the twigs (terminally or laterally), on the leaf petioles, or on the veins on the upper or under surfaces of the leaves of Quercus lobata. Figures 195, 205-206.

Occurring singly or in compact, distorted masses of as many as 8 galls, on the twigs (terminally or laterally), on the leaf petioles, or on the veins on the upper or under surfaces of the leaves of Quercus lobata.

RANGE:
California: Probably confined to a limited area including parts of Mendocino Lake, and northern Sonoma Counties, and rimming at least the northern part of the Sacramento Valley. The remarkable gall of this species is, apparently, not rare in the Mendocino-Lake County area, but it is as far as we know confined to that part of California. While often occurring on the twigs of the Valley oak, one of the two instances of a true Cynips gall in this location, it is by no means confined to the twigs as Weld suggests, for I have specimens from petioles and from leaf veins, both on the upper and under surfaces of the leaf.

The remarkable gall of this species is, apparently, not rare in the Mendocino-Lake County area, but it is as far as we know confined to that part of California. While often occur- ring on the twigs of the Valley oak, one of the two instances of a true Cynips gall in this location, it is by no means con- fined to the twigs as Weld suggests, for I have specimens from petioles and from leaf veins, both on the upper and under surfaces of the leaf. Oviposition is evidently not so unlike oviposition with other agamic forms of Cynips. Weld records fully grown galls containing immature insects as early as August. Thru the courtesy of Miss Schulthess and Mr. Leach, I have series of the galls and of the adults from a number of localities. Galls collected at Kelseyville on September 25 (in 1926) were fully grown but contained very small larvae. The galls collected at the same locality on October 4 (in 1925) contained larvae that were still not mature. The galls collected at Yorkville on October 22 and at Clover dale on October 26 (both in 1922) contained live adults in November. Adults emerged from Kelseyville material, bred at Bloomington, Indiana, from January 22 to February 5, 1926, at a season when we were having freezing tempera- tures every night and a zero temperature on one occasion. Some of the adults had already escaped from the material collected at Cottonwood by Gambs in January, but others emerged on January 23. Old galls of the previous year’s growth may be found as late as October 25 (as at Clear Lake in 1923), together with the fully-grown galls of the new generation. From one small gall I cut an adult 1.5 mm. in length. It is a miniature of the normal insect except in having fewer spots in the wings, and in being generally less hairy. Heldae has usually been considered one of the most distinct species on our Pacific Coast, and this judgment is well applied to the gall produced by this insect. But the insect, as far as I can see, and as Fullaway pointed out in his original description, is practically identical with C. multipunctata conspicua. The two occur on the same species of oak, and they alone, among all species of Cynips, produce galls on the petioles and young twigs as well as on the leaves of the oak. Conspicua is unknown and there is no other Besbicus except heldae on Q. lobata in the Mendocino-Lake County area. The galls of conspicua and heldae (see figs. 195 and 198) are identical in plan, altho they do differ so much in superficial form. These several considerations lead me to believe that heldae and conspicua are derived from the same stock, and represent the closest of existent relatives of that stock.

- Alfred Charles Kinsey: (1929) The Gall Wasp Genus Cynips©

Reference: https://www.biodiversitylibrary.org/page/53516685#page/235/mode/1up


Further Information:
Pending...

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