Biorhiza eldoradensis

Eumayria eldoradensis

Andricus eldoradensis

Acorn Gall Wasp

Cynipidae

Callirhytis

Quercus agrifolia

California

Quercus kelloggii

Oregon

Quercus wislizeni

Biology of three Callirhytis gall wasps from Pacific slope Erythrobalanus oaks (Hymenoptera: Cynipidae)

Cynipid Galls of the Pacific Slope

The North American acorn galls with descriptions of new species

Notes on American Gallflies of the Family Cynipidae Producing Galls on Acorns: With Descriptions of New Species

Callirhytis eldoradensis (sexgen)

Andricus eldoradensis sp. nov.

Gall. — Inside the acorns of Q. agrifolia. Rounded bodies or larval cells, sometimes filling the whole interior of the acorn. In shape and structure they are like those of Callirhytis fruiticola. 

Habitat: Alameda and Los Angeles Co., Cal. (A. Koebele). 

The flies of this species are from Los Angeles Co, and are labeled "from acorns of Q. agrifolia", while the galls are from Alameda Co. It is barely possible that the flies have nothing to do with the galls, but both bear the same number, 109. 

Biorhiza eldoradensis (Beutenmuller)

Andricus eldoradensis Beutenmuller

They were from Ashland, Oregon, reared from acorns of califomica of the 1914, crop, collected by P. D. Sergent on September 5. 1914. Unfortunately no acorns were preserved, but the adults were said to occur "in gall pockets on the inner surface of the acorn shells" and 8 were obtained from three acorns. The flies emerged September 5-October 7, 1914. 

Host.—Quercus agrifolia Nee, Quercus densiflora Lindley, and Quercus californica Cooper.

Gall.—The gall produced by this species is undescribed. Separate woody cells are produced in the acorns, which are somewhat distorted in shape and usually undersized (fig. 1). They are always in the lower third of the acorn and the cell is adherent to the wall of the acorn and not separable from it, projecting slightly into the interior cavity, which has a velvety lining and may contain traces of the cotyledons. An acorn may contain from one to half a dozen of these cells at various points around its periphery and the flies make separate holes to the exterior through the acorn cup. Occurs in late summer and autumn in acorns of current season's crop.

At the time the species was first described, it was associated with a stony mass of galls more or less filling the interior of the acorn, the work of a new species described in the present paper as Callirhytis milleri Weld, page 11. Although this stony gall and the Eldoradensis flies bore the same Koebele number, Beutenmueller suggested that the two might have nothing to do with each other. C. milleri produces a confluent mass of cells in the interior which can be lifted out intact; Eldoradensis produces separate cells in the base of acorn not separable from the wall. The type galls of Eldoradensis consist of one acorn of each kind. The writer has seen both species working in the same acorn, but the two types of work are easily recognized.

Habitat.—Acorns of Quercus agrifolia affected by this species have been seen by the writer at Newhall, Piru, Fillmore, in Ojai Valley, Montecito, Santa Barbara, Paraiso Springs, Los Gatos, Berkeley, and St. Helena, California. Those of Quercus wislizeni in San Gabriel River canyon above Azusa, at Santa Margarita, Los Gatos, and Bagby, California.

Biorhiza eldoradensis

The writer noted the occurrence of cells of this species in acorns of Quercus agrifolia at Ojai, Paraiso Springs, and Mount Diablo; on Q. wislizenii at Ukiah, in California Redwood Park, in the Santa Lucia Mountains, in the San Bernardino and Santa Ana (adults out September 23) Ranges, and at Idyllwild were adults emerged September 21 to October 1; on Q. kelloggii in the Sequoia National Park, in the California National Forest along the road from Upper Lake to Bartlett Springs, at Fort Jones, Scott Bar, and Milford, Calif., and at Siskiyou, Oreg. 

Field notes on gall-inhabiting cynipid wasps with descriptions of new species

Eumayria eldoradensis (Beut.). 

Quercus agrifolia, kelloggii, wislizeni
Acorn galls
Fig 43. Cells single. Exit hole thru cup.

Fig 43. Q. agrifolia (upper) and wislizeni Occurs on Q, kelloggii also. Adults emerged Sept. 21 to Oct. 1 (Idyll wild); Sept. 5 to Oct. 7 (Ashland, Oreg.).


Callirhytis eldoradensis [bisexual generation] emerges from integral acorn hull galls in aborted acorns. 

Host:
Q. wislizenii


Callirhytis eldoradensis

These monothalamous galls look like normal acorns except they may reveal exit holes and can stay on the branches long after non-galled acorns have dropped to the ground. 

This species is unusual in that the bisexual adults emerge in September and October from acorns formed in spring and summer. 

Host:
coast live oak (Quercus agrifolia)
