Endangered butterfly in San Diego County is the focus of a new protection effort

Two environmental groups have filed a petition with the state asking it to provide more protection for a once-abundant butterfly that has seen its numbers fall precipitously in San Diego County and elsewhere in recent decades.

The tiny Quino checkerspot should be added to California's list of endangered species because its remaining habitats are under threat from development projects, according to the petition, which was filed by the Center for Biological Diversity and the Endangered Habitats League.

"It's alarming that a butterfly that once filled the skies of Southern California is now only found in pockets of its former range," said Tara Cornelisse, an entomologist at the center. "With insects declining at a frightening rate, we need to protect more habitat for endangered butterflies, not allow it to be carved up piece by piece."

Well into the 1970s, the Quino checkerspot was among the most abundant butterflies in Southern California, with a range that stretched from the coast near Ventura County, east to the Tehachapi Mountains, and south to northern Baja.

Millions of them flitted about every spring, doing what butterflies do: pollinating plants and serving as meals for birds and reptiles. Scientists consider butterflies important indicators of the overall health of an ecosystem.

Construction projects—houses, business parks, shopping malls, freeways—destroyed many of the habitats and fragmented others. Nonnative plants choked off the vegetation used by the butterflies for shelter and feeding. Fire and drought worked their own mayhem.

By the late 1990s, about 75% of what the butterfly used to call home was gone. It disappeared from Los Angeles, San Bernardino and Orange counties, barely holding on in pockets of southwestern Riverside and southern San Diego counties.

The overall population fell an estimated 95 percent, and in 1997 the Quino was added to the federal endangered species list.

But that hasn't been enforced, the new petition says, and in 2002 federal wildlife officials reduced the butterfly's designated critical habitat by about 64 percent. What's left is threatened by a half-dozen pending developments in Riverside and San Diego counties, including two near Chula Vista, according to the petition, which was filed June 29.

The petition was lodged with the California Fish and Game Commission. Under the state's Endangered Species Act, officials with the state Department of Fish and Wildlife have three months to study the proposal and forward a recommendation to the commission, which would vote on it in a public hearing.

Several government agencies and conservation groups have tried in recent years to augment the butterfly population by raising caterpillars at the San Diego Zoo, placing them in protective pods and transferring them to natural habitats.