Hurricane Irma didn't hurt the endangered Key deer, but it may have all but wiped out the most endangered butterfly in Florida.

Since the storm passed through in September, only a single Miami blue butterfly, another resident of the Keys, has been spotted there, according to Marc C. Minno, co-author of the book Butterflies of the Florida Keys.

Even if a couple more turn up there, Minno said, "They're doomed. They're found only on these isolated islands in areas that take the full brunt of hurricanes and sea level rise."

However, another butterfly expert says it's too soon to tell whether Florida has seen the last of the Miami blue. Andrew Warren of the Florida Museum of Natural History suggested waiting until spring to be sure.

After all, this would not be the first time someone thought the blue-winged butterfly had become extinct. It's not even the second time.

If it turns out that this time they really are gone for good, though, there is a captive-bred group of Miami blues being tended by scientists at the museum, Warren said. Their captive breeding efforts have been supported by the sale of a specialty beer, Miami Blue Bock.

But, Warren added, "despite many attempts to establish new populations with this captive-bred stock, there is no evidence that any reintroduction attempts were ever successful. So I guess just because we have a captive colony does not guarantee they can be successfully reintroduced into the wild."

Minno said he and other butterfly experts are heading to Cuba to see if there are any still fluttering around there. He's hopeful about their prospects, based on the terrain.

The Miami blue colony in Cuba was in an area that was more protected from Irma's wrath than the small islands in the Keys where the Florida colony lived, he said.

But Warren said the Cuban colony isn't from the same sub-species, and thus no one should think it could be introduced here to replace the natives.

Not long ago the Miami blue was considered a common Florida butterfly. You could see its iridescent wings fluttering all across the southern half of the peninsula, from Tampa to Daytona Beach.

But development wiped out its habitat, including the nickerbean and wild sage that it feeds on. Insecticides intended for mosquitoes killed the blues as well. Meanwhile, invasive creatures such as iguanas and fire ants picked off the blues' larvae.

By the 1980s, the blue had been squeezed out of all but the southernmost part of the peninsula and was ranked among North America's rarest insects.

After Hurricane Andrew clobbered South Florida in 1992, the remaining colonies of the Miami blue appeared to have been completely blown away by the storm's Category 5 winds. But in 1999 a new colony turned up at Bahia Honda State Park.

Then, in 2010, that population disappeared, too, leading to fears that this at last was the end. Once again, new populations turned up at the Great White Heron National Wildlife Refuge, based on Cudjoe Key, and the Key West National Wildlife Refuge, which stretches across a series of remote islands from Key West to the Dry Tortugas.

Butterfly experts acknowledged then that one good storm could wipe them off the face of the earth and launched the breeding project at the museum, where Warren is the senior collections manager for butterflies and moths. The U.S. Fish and Wildlife Service added them to the endangered species list in 2012.

Contact Craig Pittman at craig@tampabay.com. Follow @craigtimes.