Atala Butterfly Rebounds From Possible Extinction in Florida

Summary: Successful rebounds from possible extinction in Florida for the Atala butterfly poses concerns for the near-threatened coontie as Atala's host plant.

Atala butterfly, Everglades National Park: Bill Perry/NPS, Public Domain, via Flickr

The Atala butterfly (Eumaeus atala) is rebounding so successfully from possible extinction in southeastern Florida that its dramatic resurfacing is identifying the Caribbean hotspot native as a garden pest because of its exclusive host plant relationship with Florida’s near-threatened coontie plant (Zamia integrifolia).

Atala is a subtropical-to-tropical butterfly with Caribbean nativity. Abundant populations are native to the Cayman Islands and Cuba in the western Caribbean and to Florida’s southeastern Lower Peninsula.

Silesian-born U.S. Department of Agriculture (USDA) entomologist Eugene Amandus “E.A.” Schwarz noted the Florida native insect’s abundance in 1888, in the first of the seven-volume USDA Division of Entomology’s commissioned report, Insect Life (1888 to 1895).

“By far the most conspicuous insect in semitropical Florida is Eumaeus atala, a butterfly which on account of its abundance and brilliancy in coloration can not fail to attract at once the attention of the entomological visitor,” begins Schwarz’s description of the Atala’s life history and economic significance as observed at Coconut Grove, Miami’s oldest continuously inhabited neighborhood.

Atala is also known as the coontie butterfly because of its exclusive dependence upon North America’s only native cycad for egg laying and as the caterpillar stage’s food source. Cycads are fern-like seed plants with a lengthy fossil history.

Reliance upon the coontie explains Atala butterfly’s dwindling populations after the overharvesting of coontie plants by the 1920s. Coontie ethnobotany, or uses by humans, includes sourcing as a humidity- and temperature-tolerant starch. By the 1920s, a coontie hot spot along the New River’s path through Fort Lauderdale to the Atlantic Ocean had been stripped to the ground. By the mid-1930s, the specialist butterfly was viewed as a rare native species in Florida. Sporadic sightings occurred until the mid-1960s. For more than a decade Atala was considered to be extinct.

Recovery began in 1979 with discovery of a small Atala butterfly colony on one of coastal Miami’s barrier islands. Roger L. Hammer, senior interpretive naturalist for Miami-Dade County Parks and Recreation from 1977 to 2010, rediscovered the hairstreak butterflies, with their distinctive underside streak of blue dots, on Biscayne Bay’s Virginia Key.

“As far as we know, every extant colony in South Florida originated from that colony,” Sandy Koi, lead author of an Atala reintroduction study, explains March 21, 2016, in editor Richard Levine’s Entomology Today blog post. “It is only because of the dedication of scientists and local citizens that the butterfly has recovered to the point that it may be considered a pest in botanical gardens and developments that use the also-recovering coontie plants as ornamental landscaping.”

Atala’s historical range favors southernmost peninsular Florida’s pine rockland habitats and tropical hardwood hammock edges. Atala butterflies and their special coontie plants historically flourished in the pine rocklands and waterways that once dominated southeastern Florida’s low elevation portion of the Atlantic Coastal Ridge. These favored habitats have mostly disappeared as a consequence of agricultural and urban development.

Koi and co-author Jaret Daniels, assistant professor at the University of Florida and assistant director of the Florida Museum of Natural History in Gainesville, note in their study the periodic, unpredictable crash-eruption cycles that apparently characterize Atala’s life history. The butterfly’s sensitivity to extreme weather is another factor that drives range-extension considerations inside and outside the scientific community.

“It is currently found in small colonies as far north as Martin County, introduced by individuals with little or no scientific reason for doing so; however, the butterfly is found in scattered self-established or reintroduced colonies from Palm Beach to Broward and Miami-Dade Counties,” observe Koi and Daniels in the study, published online December 2015 in Florida Entomologist.

“There has been discussion among scientists both in favor of and in opposition to introducing Atala colonies outside of its historical range,” the authors add. “It may prove beneficial to extend its range in the event of a devastating weather event and limited remaining habitat; on the other hand, it may be detrimental to local nurseries that raise and sell cycads, botanical gardens, homeowner landscaping, and local biota.”

Southern Florida gardens featuring coontie plants may be themed around native flora or around native edible plants or specifically around butterfly host plants. Visits by Atala butterflies are not welcome in individual and botanical gardens designed to preserve native flora or to grow edible native plants. Gardens specifically attracting butterflies such as the Atala include coonties on the nectar menu.

“I have this butterfly in my garden since I grow the host plant,” Thomas Chouvenc, a research assistant at the University of Florida Fort Lauderdale Research and Education Center (UF/FLREC/IFAS) in Davie, says in Levine’s March 21st blog post. “It’s a delight to see them fly around. The plants get munched, but they always come back.”

Sandy Koi aims at a recovery process that satisfies pro-coontie gardens as well as pro-Atala, pro-coontie gardens.

“I have been using this fact in order to implement an integrated pest management method,” Koi shares with editor Richard Levine, who is communications program manager at The Entomological Society of America. “Along with dedicated volunteers, we remove the unwanted colonies of both plants and butterfly immature life stages, and install the removed pupae or larvae into the gardens that want to host them.”

Sebastian Inlet State Park, east central Florida: Florida State Parks @FLStateParks via Twitter March 23, 2016

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Atala butterfly: Bill Perry/NPS, Public Domain, via Flickr @ https://www.flickr.com/photos/evergladesnps/8721412998/

Sebastian Inlet State Park, east central Florida: Florida State Parks @FLStateParks via Twitter March 23, 2016, @ https://twitter.com/FLStateParks/status/712643888255787008

For further information:

Florida State Parks @FLStateParks. "This Atala Hairstreak butterfly was spotted at Sebastian Inlet State Park. Photo by Ed Perry." Twitter. March 23, 2016.
Available @ https://twitter.com/FLStateParks/status/712643888255787008

Koi, Sandy; and Donald W. Hall. “Eumaeus atala.” University of Florida Entomology and Nematology Department. Featured Creatures. November 2015.
Available @ http://entnemdept.ifas.ufl.edu/creatures/BFLY/Eumaeus_atala.htm?platform=hootsuite

Koi, Sandy, and Jaret Daniels. “New and Revised Life History of the Florida Hairstreak Eumaeus atala (Lepidoptera: Lycaenidae) with Notes on its Current Conservation Status.” Florida Entomologist, vol. 98, no. 4: 1134–1147. December 2015. DOI: http://dx.doi.org/10.1653/024.098.0418
Available @ http://www.bioone.org/doi/10.1653/024.098.0418

Levine, Richard. “A Nearly Extinct Butterfly Makes a Comeback in South Florida.” Entomology Today. March 21, 2016.
Available @ http://entomologytoday.org/2016/03/21/a-nearly-extinct-butterfly-makes-a-comeback-in-south-florida/

plantwallah. "Coontie Hairstreak Butterfly (Eumaeus atala) on Zamia." YouTube. July 2, 2008.
Available @ http://www.youtube.com/watch?v=hq-b_UAhS3E

Schwarz, E.A. (Eugene Amandus). “Notes on Eumaeus Atala.” Insect Life, Vol. I: 37-40. Washington DC: Government Printing Office, 1888-9.
Available via Biodiversity Heritage Library @ www.biodiversitylibrary.org/page/14959728