Imperiled Butterflies: Miami Blue

About 150 butterfly species are found throughout Florida. 15 of those species are found only in extreme southern Florida and the Florida Keys. Continued expansion of urban development and widespread use of pesticides used to control mosquito populations have put many of these species in jeopardy.

This is part one of a seven part series covering Florida’s imperiled butterflies. Look for these posts on Fridays for the next six weeks.

Miami Blue

The Miami Blue (Cyclargus thomasi bethunebakeri) is a tiny butterfly native to  coastal southern Florida and was once very common within its range. This species is very short lived and may only range some 30 feet from the spot where its egg was laid. Bright shimmering blue upper wings marks males of the species and the underside of the wings are patterned with white and gray with circular black spots.

Habitat loss and fragmentation due to urban development and the reduction of larval hosts like  Balloonvine (Cardiospermum corindum) reduced the populations of this species and by 1990 no Miami Blue butterflies were believed to remain in peninsular Florida or the barrier islands.

Increasingly rare even in the Keys, the population was thought to be entirely destroyed by Hurricane Andrew in 1992. In 1999 a small colony of Miami Blue butterflies was found in Bahia Honda State Park and it seemed that perhaps only 50 of these butterflies still existed in the wild.

The University of Florida in conjunction with other agencies began a captive breeding program. Miami Blue butterflies were released back into the wild and small but steady populations could be found on Bahia Honda and in several locations in the Florida Keys. Recent years have seen these populations again reduced and this butterfly species is in danger of extinction.

The North American Butterfly Association has a fund where people can donate to support programs like captive breeding and habitat conservation for the Miami Blue butterfly. You can learn more about this species at the Butterfly Conservation Initiative website Miami Blue butterfly page.