Resident urges short-term protections for pipevine swallowtail caterpillars in Bidwell Park

David Simon, a local resident who submitted a letter to the commission, urged the Bidwell Park and Playground Commission to take steps to protect pipevine swallowtail caterpillars during their spring breeding and migration period.

“Usually mostly on Peterson, but both sides … there is literally dozens of them that are squashed on the roadway,” Simon said, describing observations of caterpillars being run over by vehicles and asking the commission to consider temporary protections during the peak period. He said the prime time for the migration is in May and suggested short closures of park roads, or at minimum, public outreach and volunteer rescue efforts.

Commissioners asked whether the insect is native and whether car mortality posed a significant threat. Simon said the pipevine swallowtail in the area breeds on the pipevine plant and that females will lay eggs only on that plant; if eggs are laid on other plants, the caterpillars will not survive. He acknowledged he is not a biologist but urged protective steps during the peak period.

Several commissioners suggested lower-impact responses: advance public education, temporary signage (“Caterpillar migration time — please drive carefully”), press outreach and engaging volunteers such as the PALS (Partners, Ambassadors, Leaders and Stewards) program to rescue caterpillars, rather than immediate road closures. One commissioner encouraged Simon to bring the issue to the next City Council open time to seek broader policy or operational changes.

The commission did not take formal action on the request at the meeting; commissioners indicated staff could pursue outreach and that the resident should consider speaking at City Council to seek additional authority for closures if needed.