Andricus crystallinus

Gall:
The galls in which the bisexual generation of Andricus crystallinus develops are found mostly on the upper surface of leaves, singly or in small groups. The color is green with straw-colored apex. The gall has many long cottony, white hairs which project laterally and are longer than the greatest dimension of the gall. The gall is conical in shape, and distinctly canted to one side rather than being erect. The length is approximately 2.5 mm. with the base 1.0 mm. tapering to the tip. The position of the gall is indicated on the opposite (usually lower) side of the leaf by a pale-colored elliptical swelling.

Emergence takes place from the uppermost side of the slanted, conical gall. The gall has a single chamber.

Hosts:
Quercus douglasii
Quercus dumosa
Q. garryana

Andricus crystallinus (bisexual generation)

Hosts:
Quercus dumosa
Quercus douglassi
Quercus garryana
Quercus durata

Andricus crystallinus (bisexual generation)
[Page 109]

Noticeable green, conical, slightly curved, monothalamous galls with cottony fibers develop on the upper surfaces of leaves. These galls of the bisexual generation superficially resemble individual galls of the unisexual generation.

Hosts:
Quercus douglasii
Quercus berberidifolia
Quercus durata
Quercus garryana

Feron crystallinum (Bassett, 1900) comb. nov.

Gall. Sexual galls (Fig. 148–149) monolocular, they are mostly on the upper surface of leaves, singly or in small groups, green with straw coloured apex, conical, slightly curved. The gall has numerous long cottony, white hairs projecting laterally, which are longer than the greatest width of the gall. The gall is 2.5 mm in length, with the base 1.0 mm tapering to the tip. The position of the gall is indicated on the opposite (usually lower) side of leaf by a pale coloured elliptical swelling (Doutt 1960). The gall is difficult to distinguish from other similar sexual galls such as F. comatum, F. dumosae and F. kingi.

Biology. Alternate asexual and sexual generations were matched by Doutt (1960). Alternate sexual and asexual generations are also confirmed herein using DNA data, with four individuals (three asexual females, one sexual female) sequenced for cytb and three individuals (two asexual females, one sexual female) sequenced for cytb. Cytb sequences grouped into two haplotypes that were 0.23% divergent (GenBank accessions KX683596, MZ030743, OQ446195–OQ446196) and ITS2 sequences were identical among the three individuals (GenBank accessions OQ448237–OQ448239). Asexual galls in autumn on leaves, adults emerge in January–February; sexual galls in spring, adults emerge in March. Both generations develop on oaks from section Quercus, subsection Dumosae: Q. douglasii, Q. dumosa and Q. garryana.

Distribution. USA: California.