Andricus reticulatus
(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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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
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Last updated Feb 4, 2026 1:47 PM UTC
New Cynipid Wasps from California (Hymenoptera: Cynipidae)
Robert J Lyon
(1984)
Andricus reticulatus
Hosts: Quercus engelmanni
This species, originally described by Bassett, 1890, has been recorded from a number of white oaks in the Southwest (Arizona, New Mexico and West Texas). The cynipids of the Southwest have been considered to be sharply separated from those of the Pacific Slope; therefore it is surprising to find this species producing galls on Quercus engelmanni Greene in Southern California (Fig. IB). Specimens were collected on a number of trees near Los Angeles and Pasadena with the insects emerging in late February. Infestation was particularly heavy on some trees, usually younger ones, and in several instances, the trees were nearly defo¬ liated. Female wasps were ovipositing in the unopened buds on 23 February in La Canada, California. These sites were marked with colored thread and with the opening of the new leaves, 23 March the young galls were immediately visible. The young galls were covered with pinkish, white hairs and growth was rapid so that galls were full sized by 23 April although the developing larvae were still small. The appearance of the new galls only one month after emergence of the adults indicates that an alternate bisexual generation does not exist in this species, at least in this area. The adult females were compared with paratypes of Andricus reticulatus Bass, from New Mexico and they appear to be the same, although the notaulices are incomplete in some specimens from Quercus engelmanni. Lewis Weld collected this California Andricus reticulatus many years ago and his notes indicate that he could not separate it from Arizona specimens. Figure 172 in “Cynipid Galls of the Pacific Slope,” Weld, shows the gall as an undescribed species but notes similarity to Andricus reticulatus Bassett and an Eastern species, Andricus petiolicola (O.S.). There are twelve specimens of the California reticulatus in the Weld collection. Charles Dailey has sent in females of this species from galls collected on Quercus turbinella Greene, ssp. turbinella Tucker growing at El Condor, Baja California, Mexico and also from a hybrid oak, Quercus dumo- sa x Quercus turbinella Greene, ssp. California Tucker growing at Gorman, Cal¬ ifornia. They are typical Andricus reticulatus Bass.