Feron dumosae
(sexgen)sexgen:The sexual generation (AKA bisexual generation or sexgen) of an oak gall wasp (cynipini) species consists of both male and female wasps, which mate before the females lay eggs which will mature to form the all-female agamic generation.
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Location: petiole, lower leaf, between leaf veins, leaf edge
Form:
Cells: monothalamous
Possible Range:
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.
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Common Name(s):
Plate Gall Wasp (bisexual generation)
Created Feb 4, 2026 1:47 PM UTC
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Last updated Feb 4, 2026 1:47 PM UTC
Alternate generations of gall cynipids (Hymenoptera: Cynipidae) on Garry oak
David Evans
(1972)
Andricus pattersonae
Bisexual generation
[Photos of this gall appear on page 12 of the pdf]
On the margins of young leaves, occasionally submarginally, more frequently on the basal section of the leaf, rarely on the leaf stem; more commonly on the lower leaves of small trees. Individual galls about 3x1 mm, eccentrically fusiform-ellipsoidal, apex attenuated and curved; the surface densely micro-spinose. Immature galls pale green, maturing to dark red. Single monothalamous, but sometimes in groups of 2-4, possibly 8 or 9 on a leaf. Emergence hole is at the upper end of the gall, below the apex. Parasitized galls are often more globular and variable in size, usually brighter red.
Range: west-central CA
Adults of the bisexual generation emerge during late May to early June, and females oviposit on the undersides of leaves. Galls that are too crowded develop at an uneven rate and many do not mature. The agamic females may emerge the following spring, late March to early April; however, a diapause within the gall for 1 or 2 years is common.