Citation: Downing, J., H. Borrero, and H. Liu. 2016. Differential impacts from an extreme cold spell on subtropical vs. tropical specialist bees in southern Florida. Ecosphere 7(5)

Tropical forest ecosystems are rich in epiphytes that make up a significant portion of the overall plant diversity. However, epiphytic plants are often understudied due to inaccessibility and the lack of basic ecological information poses challenges to their conservation, particularly in a time of rapid global change. The mule-ear orchid, Trichocentrum undulatum (Orchidaceae), is a large flowering epiphyte found in southern Florida (USA), the Greater, and Lesser Antilles including Cuba. The plant is Florida state-listed as endangered with only one remaining small and declining population in a coastal mangrove forest due to historical extraction and habitat destruction. Currently, there is no systematic understanding of the species’ habitat requirements. To fill this void, we compared the habitat and microhabitat of the species on its northern distribution edge (southern Florida) and the core range (in Cuba). The Florida population has only one host species, Conocarpus erectus, found in one habitat type. This is in sharp contrast to the 92 documented hosts and 5 habitats across 8 provinces in Cuba. Based on our findings from Cuba, we suggest conservation and restoration options in Florida by proposing potential suitable host plants and habitats. Proactive restoration of this species will help to ease the threat from sea-level rise to the species by securing and expanding range margins.

Inflorescence stalk herbivory on the Mule Ear orchid (Trichocentrum undulatum) has been observed in Cuba, which resembles the specialized herbivory interaction seen in southern Florida between a specialized dipteran, Melanagromyza miamensis (Agromyzidae) and the Mule Ear orchid. We are able to identify the inflorescence herbivore to be the genus Melanagromyza. It is possibly the same species that can be found in southern Florida. The mule-ear orchid is endemic to the Caribbean region, i.e. Cuba, Jamaica and southern Florida. To our knowledge, this is the first report of an apparently specialized inflorescence stalk herbivory by Agromyzid flies on the Mule Ear orchid in Cuba. The herbivory can partially or completely destroy the flowering potential of the impacted plants.