At its August 13-14 meeting, the California Fish and Game Commission (the Commission) unanimously determined that a petition to list the Quino checkerspot butterfly (Euphydryas editha quino) (QCB) as endangered throughout its range in California provides sufficient scientific information to indicate that the petitioned action may be warranted, thereby officially granting the QCB “candidate” species status under the California Endangered Species Act (CESA). The Commission published its Notice of Findings of Candidacy on August 20, 2025, and the QCB formally obtained CESA protections on August 30, 2025.

The QCB was once the most common butterfly in Southern California, ranging from coastal Los Angeles and Orange Counties, west to Riverside and southwestern San Bernardino Counties, and south to San Diego County. However, by 1997, the QCB was extinct in Los Angeles, Orange, and San Bernardino Counties. Today, it is found in small areas in the foothills of southern San Diego and in southwestern Riverside.

The candidacy designation temporarily affords the QCB broad CESA protections (including prohibitions against “take” without permit authorization) throughout California over the next 12-18 months while the California Department of Fish and Wildlife (CDFW) conducts a species status review to confirm whether listing is warranted and to recommend management and recovery actions.

PETITION

The Commission made its determination in response to a petition filed by the Center for Biological Diversity and Endangered Habitats League on December 18, 2024 (the Petition) and a subsequent evaluation by CDFW in February 2025 recommending that the Commission accept the Petition for further consideration under CESA. The QCB has been listed on the federal Endangered Species Act since 1997 and was the subject of a previous 2020 CESA petition, which was eventually withdrawn by petitioners after a superior court decision on a different matter held that insects are not eligible for listing under CESA.

The Petition argues that the United States Fish and Wildlife Service (FWS) has failed to properly protect the QCB. In 2002, FWS designated 171,605 acres of critical habitat for the QCB but despite further QCB population declines and loss of habitat, the FWS later reduced the designated critical habitat to 62,125 acres (a 63.8 percent decrease), a decision that the Petition asserts was based largely on economic reasons.

Furthermore, the Petition alleges that regional habitat conservation plans, including the Western Riverside County Multiple-Species Habitat Conservation Plan (MSHCP) and the San Diego County MSHCP, have inadequate protections and resulted in loss of core habitat areas. Thus, the Petition requests that the Commission list the QCB as endangered throughout its entire range in California.

CANDIDATE SPECIES PROTECTIONS

Under CESA, candidate species are afforded the same broad legal protections as listed species. In particular, the “take” of a listed or candidate species is strictly prohibited without express authorization. “Take” is defined as “[h]unt, pursue, catch, capture, or kill, or attempt to hunt, pursue, catch, capture, or kill (Fish & Game Code, § 86.). Civil and criminal penalties for unauthorized take violations are significant.

Project proponents typically acquire take authorization through an Incidental Take Permit (ITP) issued by CDFW under Fish & Game Code Section 2081. An applicant must demonstrate that the take is “incidental” to an otherwise lawful activity, that all impacts from the take will be minimized and fully mitigated, and that sufficient funding is available to implement minimization and mitigation measures. CDFW will not issue an ITP if it determines that a project would “jeopardize the continued existence” of the listed species covered by the permit.

NEXT STEPS IN CESA LISTING PROCESS

CDFW is now required to begin a 12-month status review of the QCB. The review will result in a written report to the Commission addressing whether listing is warranted, identifying essential habitat, and recommending management activities and recovery actions. The status review must rely solely on best available scientific data (economic considerations are excluded) and must undergo peer review.

Once CDFW finalizes and publishes the status review, the Commission will hold a public hearing and determine the scope and extent of CESA legal protections for the species, if any. If the Commission concludes that listing is warranted, it will publish a notice of finding and initiate rulemaking to add the species to protected CESA status.