About Cynips divisa Hartig, 1840
The scientific name of this species is Cynips divisa Hartig, 1840. Red-pea galls (also called red currant galls) are chemically induced growth distortions that form on the underside of the midrib of veins on oak (Quercus) species, and attach to the leaf via a short stalk or peduncle. The red-wart gall is the structure produced by the sexual generation of this same species. In the species' life cycle, most agamic adult wasps emerge in October. After overwintering, Cynips divisa develops eggs parthenogenetically; these eggs develop inside live oak buds, forming red-wart galls. Infested buds turn yellow, orange, or russet, and reach about 4 mm (0.16 in) in length. Red-wart galls become visible in May, and males and females of the bisexual generation emerge in June. These adults produce fertilized eggs that then develop into red-pea galls.
