Endangered Keys butterflies get boost
July 25, 2018
FLORIDA KEYS —The wild-lime and torchwood treesthat grow abundantly in John Pennekamp Coral Reef State Park and Dagny Johnson Key Largo Hammock Botanical State Park are the preferred meal choice of hundreds of lab-raised Schaus’ swallowtail caterpillars that were released by biologists on Monday.
Biologists and researchers from the Florida Department of Environmental Protection and U.S. Fish and Wildlife Service, the Florida Parks Service, and Florida Museum of Natural Historyat University of Florida have all worked collaboratively on raising thousands of Schaus’ swallowtail and Miami blue butterfly pupa to bolster their numbers and give the endangered species a better chance of survival.
Schaus’ swallowtail is restricted to only a few remaining sites in Florida Keys, making it one of the rarest butterflies in the U.S. and the only federally listed swallowtail. Habitat loss has led to severe population declines and has greatly reduced its range.
A mature Schaus’ swallowtail caterpillar is about two inches long, dark brown with white and yellow lateral blotches, a white underbelly and lined with tiny symmetrical blue dots.
They have large eyes and a voracious appetite.
“They devour a tremendous amount of food,” Florida Museum of Natural History researcher Jaret Daniels said.
The dozens of cups that transported the caterpillars from Daniels’ lab in Gainesville were packed with wild lime. Daniels said they’d eat the entire cup within a day or two and that the larvae should pupate withinfive to seven days.
The Schaus’ will stay in its cocoon for months and emerge with the rainy season.
“They’ll stay in there for a year if we don’t get much rain,” said Kristen Rosetti, a research assistant at the Florida Museum.
Daniels said they can easily be tricked by being sprayed with water, which may need to be the case.
“They also drink copious amounts of water,” he said.
When the Schaus’ swallowtail does finally emerge, it will live for about two weeks with the hopes of reproducing. And biologists will track them.
The Schaus’ swallowtail is one of the largest swallowtail butterfly species, which a maximum five-inch wing span. In 2012, there were only four foundby researchers in their naturalrange, from Elliott Key to northern Key Largo.
Mark Salvato with the U.S. Fish and Wildlife Services saida female during her short lifespancan lay up to 500 eggs, but less than 2 percent will make it to adulthood.
Next month, biologists will release adult Schaus’ swallowtails at Pennekamp to further helplocalnumbers.
The group of biologists also released about 150 Miami blue butterfly chrysalises on Tuesday on Long Key,or rather placed.
The pupae are attached to corrugated cardboard and safely tucked in PVC tubes capped with mesh wiring. When the little butterfly emerges from its cocoon, roughly the size of a large peppercorn, it will fit through the wiring unharmed.
“The Miami blue is about the size of a thumbnail,”Daniels said.
Salvato said there have been a few Miami blue butterflies documented off the coast of Key West, but other colonies, including one on Big Pine Keya few years ago,have been decimated.
“Expanding coastal development over the last several decades led to a catastrophic decline in the butterfly’s overall range,”aU.S. Fish and Wildlife Servicesrelease said.
“The butterfly inhabits beachside scrub in close association with its two common larval host plants, Florida Keys blackbead and gray nickerbean. The tiny, slug-like larvae are regularly tended by ants which provide protection from various insect predators in return for sugary food rewards.”
Salvato said there are 30 butterflies federally listed as endangered with four endemic to the Keys: the Schaus swallowtail, Miami blue butterfly, Bartram’s scrub-hairstreak and the Florida leafwing.