Cecidology
Guides
Andricus stropus
leafy-wreath gall
Andricus stropus is a species of cynipid gall wasp in the family Cynipidae that induces distinctive galls on oak trees. The species is part of the highly diverse Andricus genus, which contains numerous oak-associated gall wasps, each producing characteristic gall structures. Like other cynipids, A. stropus has a complex life cycle involving manipulation of plant tissue through chemical secretions that redirect host oak growth patterns. The species is known from observations primarily in North America.
Atrusca capronae
striped oak-apple gall wasp
Atrusca capronae, commonly called the striped oak-apple gall wasp, is a cynipid wasp species that induces characteristic galls on oak leaves in southwestern North America. The species is most frequently observed in Arizona but occurs throughout the region where its host plants grow. The wasp's common name derives from the striped appearance of the galls it produces, though stripe intensity varies geographically. The species is considered fairly common within its range.
Callirhytis congregata
sausage flower gall wasp
Callirhytis congregata is a cynipid gall wasp native to California that induces distinctive galls on the catkins of three oak species: coast live oak (Quercus agrifolia), interior live oak (Quercus wislizeni), and canyon live oak (Quercus chrysolepis). The species was originally described by William Harris Ashmead in 1896 under the genus Andricus. It is considered locally common within its range. The galls are described as rugose, yellowish-brown woody swellings with multiple cells, appearing to grow from the tips of slender twigs with a long peduncle-like base.