''Cynips quercusechinus'', the urchin gall wasp, is a species of

gall wasp Gall wasps, also incorrectly called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this generall ...

in the family

Cynipidae Gall wasps, also incorrectly called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this gener ...

. It induces its

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external Tissue (biology), tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissu ...

s, which resemble

sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) ...

s, on the leaves of

oak trees An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably '' ...

. These galls are about 10mm in diameter. The galls fall with the leaves in autumn, and the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. Th ...

e inside of them emerge as adults in the spring. This species was first described by

Carl Robert Osten-Sacken Carl Robert Osten-Sacken or Carl-Robert Romanovich, Baron von der Osten-Sacken, Baron Osten Sacken (21 August 1828, – 20 May 1906) was a Russian diplomat and entomologist. He served as the Russian consul general in New York City during the A ...

in 1870 based on specimens from

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

References

Cynipidae Gall-inducing insects Fauna of the San Francisco Bay Area Insects described in 1870 Taxa named by Carl Robert Osten-Sacken Hymenoptera of North America {{wasp-stub