Andricus weldi
(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).
View in glossary →
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.
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.
Created Feb 4, 2026 1:47 PM UTC
•
Last updated Feb 4, 2026 1:47 PM UTC
Cynipid Galls of the Chicago Area
LH Weld
(1928)
Cynips weldi
A globular cluster, 8-20 mm in diameter, on under side of petiole at its junction with the leaf blade, consisting of a dozen or more reddish brown galls, closely pressed together, tuberculate at the distal end, flattened at the sides, tapering to the point of attachment, dropping to the ground in late Sept or Oct before the leaves. On trees of Q alba. The emergence of the flies is in March or early April and distributed over a period of five or six years, none probably appearing until the second spring.