Andricus gigas

The tan, conical, bisexual generation galls produced occurred on the staminate flowers and occasionally in leaves (Fig. 1). Those at the base of staminate flowers were often hidden by bud scales.

Field observations and rearings have shown the bisexual generation of Andricus crenatus Weld (1952) is Andricus gigas Kinsey (1922). Because Kinsey erroneously described a toothed tarsal condition, Weld (1951) transferred A. gigas to Dryocosmus Giraud. Due to the actual toothed tarsal claws of both generations, the species is now returned to the original placement in Andricus Hartig. The valid name again becomes Andricus gigas.

Host:
Quercus douglasii

Dryocosmus gigas

Quercus douglasii
Flower galls
Not distinguished from the above in the field.

Andricus gigas, new species

Galls (Pl. XXIV, Fig. 14). --Small, brown, egg-shaped cells scattered in the aments. Each cell monothalamous, naked, only microscopically granulate, well pointed at the apex, thin-walled and hollow. Apparently tremendous enlarged anthers, about 1 mm in diameter by 2 mm. long. Scatteringly in aments of Quercus douglasii.

RANGE.-California: Merced Falls.

The galls were just maturing on March 28. Because of the location and structure of the galls, this form of the insect must complete its history in a month or two; there is undoubtedly an alternate generation, probably agamic.

Andricus gigas (bisexual generation)
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By April, bisexual-generation galls develop on the staminate flowers and leaves. These galls are conical, tan, and about 3 mm in high.

Hosts:
Quercus douglasii
Quercus berberidifolia
Quercus engelmannii

Feron gigas (Kinsey, 1922), comb. nov.

Galls. Sexual galls are small, 1–2 mm in diameter, round, pale yellow, on catkin coming off catkin stem at same place as stamens, sometimes on edge of leaf.

Biology. Alternation of sexual and asexual generations was determined by Dailey & Sprenger (1973a). Alternate sexual and asexual generations are also confirmed herein using DNA data, with four individuals (three asexual females, one sexual male) sequenced for cytb and three individuals (two asexual females, one sexual male) sequenced for cytb. Cytb sequences were on average 0.82% divergent (range 0–1.66%; GenBank accessions KX683598, OQ446198–OQ446199) and ITS2 sequences were identical among the three individuals except for two additional bases within a polyA region in one sample (GenBank accessions OQ448240–OQ448242).

This species induces galls on Q. douglasii and Q. dumosa (section Quercus, subsection Dumosae). Young asexual galls are present in August, mature in autumn; asexual adults emerge in February. Sexual galls are mature in April; adults emerge by the end of April.

Distribution. USA: California.