The Miami blue butterfly (Cyclargus thomasi bethunebakeri), once common throughout coastal south Florida, experienced dramatic population declines in the 1980s and 90s and was listed as federally endangered in 2012. Currently, the Miami blue is restricted to several remote islands in the Lower Florida Keys. The Florida Museum of Natural History currently has a captive colony of this butterfly and is working to answer questions about its ecology in order to better inform reintroduction efforts for this organism. We are conducting in-situ experiments to examine life history and demographic factors that are necessary to understand in order to inform ongoing population restoration efforts.
Since the extant wild populations of this endangered butterflies are remote and difficult to access on a consistent basis, these experiments were conducted in an outdoor enclosure located within the former range for this butterfly in order to approximate natural environmental conditions for this butterfly while excluding most predators and parasitoids. Survival, larval growth, oviposition preference, and development time were measured over several months were measured over multiple generations of captive-bred Miami blue butterflies.
Results/Conclusions
Work is ongoing and results are only preliminary, but it appears that Miami blue larvae develop more quickly when reared on grey nickerbean (Guilandina bonduc) compared to Florida Keys blackbead (Pithecellobium keyense) and the resulting adults are significantly larger in size, which could have fitness and dispersal implications. Additionally, it seems that adult females prefer to oviposit on G. bonduc over P. keyense. This apparent host plant preference has interesting applications for population restoration since the current range for the Miami blue butterfly contains almost exclusively P. keyense with very little G. bonduc present at those sites. We hope to further examine both plant species’ roles in the survival of this subspecies