Cynips quercusechinus

{{Short description|Species of wasp}}

{{Speciesbox

| name = Urchin gall wasp

| image = Cynips quercusechinus.jpg

| image_caption = Gall formed by Cynips quercusechinus

| genus = Cynips

| species = quercusechinus

| authority = Osten Sacken, 1870

| synonyms = Antron quercusechinus

}}

Cynips quercusechinus, the urchin gall wasp, is a species of gall wasp in the family Cynipidae. It induces galls in the leaves and leaf buds of blue oak and scrub oak. Like other oak gall wasps, it has two generations: a bisexual generation, and a parthenogenic female generation. In spring, the hatching bisexual generation produces hollow green galls in leaf buds. In summer, the unisexual generation induces its galls, which are red or pink and resemble sea urchins, on the undersides of leaves. These galls are about {{Convert|10|mm|in}} in diameter.{{Cite web|title=Species Cynips quercusechinus - Urchin Gall Wasp|url=https://bugguide.net/node/view/135715|access-date=2020-12-28|website=bugguide.net}} The galls fall with the leaves in autumn, and the larvae inside of them emerge as adults in the spring and lay their eggs.{{Cite web|last=Russo|first=Ron|title=Bay Nature Magazine: Otherworldly Growths on Oaks are the Sign of Galls|url=https://baynature.org/article/call-of-the-galls/|access-date=2020-12-28|website=Bay Nature|language=en-US}}{{Cite book |last=Russo |first=Ronald A. |url=https://www.worldcat.org/oclc/1239984577 |title=Plant galls of the Western United States |date=2021 |publisher=Princeton University Press |isbn=978-0-691-21340-8 |location=Princeton, New Jersey |pages=311 |language=en |oclc=1239984577}}

This species was first described by Carl Robert Osten-Sacken in 1870 based on specimens from California.{{Cite journal|last=Osten-Sacken|first=Carl Robert|date=1870|title=Contributions to the natural history of the Cynipidae of the United States and their galls|url=https://www.biodiversitylibrary.org/page/7541948|journal=Transactions of the American Entomological Society|volume=3|pages=54–64}}