Andricus incertus

Family: Cynipidae | Genus: Andricus
Detachable: detachable
Color: brown, green
Season: Fall, Summer
Location: fruit
Form: pip
Possible Range:i
Common Name(s):
Andricus fimbriatus
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Notes on American Gallflies of the Family Cynipidae Producing Galls on Acorns: With Descriptions of New Species

Andricus fimbriatus, new species


Host.--Quercus bicolor

Gall.--This fimbriate-cup gall on bicolor was well described by Riley in 1877 along with a similar one but protruding farther, from a smooth cup on Q. prinoides. Both have often been referred to in literature frequently under the names glandulus and glandulosus. The fly described as Andricus glandulus Beutenmueller, of which the author has a cotype, and associated with the above gall is a red species from an unknown gall. It belongs to the genus Callirhytis and is closely related to C. operatola — the agamic generation of C. operator (Osten Sacken).

Habitat. — The type material was collected at Wilmette, Illinois, September 1, 1917, when the galls were dropping to the ground. "When some of the galls were cut open just a year later about half still contained larvae and half pupae and adults. One fly emerged in cage March 25 and one April 18, 1919. On December 2, 1919, five living flies were cut out. Transformation thus occurs in fall and emergence in the spring and the emergence is distributed over two seasons. As the emergence is before flowering there must be an alternating generation in a vernal gall. In 1908 the galls had nearly finished dropping by September 9 and in 1912 they had all dropped by September 10. They have been seen also at Evanston, Kenilworth, and Glencoe, Illinois, and at Porter, Indiana. The herbarium at Shaw Botanical Garden, St. Louis, has a specimen from Kimmswich, Missouri, collected in 1860.

The writer has field notes on a similar gall on nine other white oaks of the eastern United States where the recess in which the gall rests is not fimbriate and the gall protrudes half its length or more. See plate 3, figure 12, on prinus [montana] and figure 13 on macrocarpa. As he has not been able to rear any of these as yet it is not known whether any or all of these are caused by the above-described species or which if any is glandulus Beutenmueller.

- LH Weld: (1922) Notes on American Gallflies of the Family Cynipidae Producing Galls on Acorns: With Descriptions of New Species©


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