Andricus schickae
(agamic)agamic:The agamic (AKA unisexual) generation of an oak gall wasp (cynipini) species consists of only female wasps, which do not mate before laying the eggs which become the male and females of the sexual generation (sexgen).
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The gall's range is computed from the range of all hosts that the gall occurs on. In some cases we have evidence that the gall does not occur across the full range of the hosts and we will remove these places from the range. For undescribed species we will show the expected range based on hosts plus where the galls have been observed.
This gall may have been induced by either Andricus schickae or Andricus occultatus; on Quercus lobata, the two are not distinguishable by gall alone. It is included here as a plausible illustration of the gall's form but is not a confirmed observation
Our ID Notes may contain important tips necessary for distinguishing this gall
from similar galls and/or important information about the taxonomic status of
this gall inducer.
Diagnosis. Galls closely resemble those of Andricus occultatus, but the adults are different. Also closely resembles A. columbiensis.
Gall. (Fig. 232). A cryptic unilocular gall within a swollen terminal or lateral bud, whose scales remain intact and surround the gall. The gall is ca. 2–2.5 mm long and 1–1.5 mm in diameter, and consists only of the larval chamber, with a thin woody wall.
Biology. Alternate asexual and sexual generations are known. The asexual generation bud galls develop on Q. garryana, mature in November, adults emerge the following spring. The sexual generation galls (Figs. 233–234) were found on Q. lobata leaves in late March-April; adults emerge soon afterwards. We expect both generations can be found on both Q. lobata and Q. garryana.
Distribution. USA, California (Los Molinos, Stockton, Cosumnes River Preserve) and Canada, British Columbia (Victoria).
