Conservation Research



Conservation of Homerus - Largest Swallowtail of the Americas

The endangered Homerus Swallowtail, once common in Jamaica, is struggling to recover with the aid of forest conservation efforts. This large (over 6 inches wide) endangered butterfly (Papilio homerus) once inhabited 7 of the 13 parishes of Jamaica and was relatively common in the 1930s. Today it occurs only in two parishes where the Blue Mountains meet the John Crow Range (eastern Jamaica) and in isolated places in Cockpit County (western Jamaica). Homerus larvae require humidity close to 100% and inhabit wet limestone forests and lower montane rainforest. Destruction of these forests led to decline of the species.

Despite existing logging prohibitions, in 1979 a government-sponsored company began cutting 2,000 hectares of rainforest a year to plant Caribbean pine. A 1984 film about the vanishing swallowtail prompted new research and conservation efforts. In 1991, Jamaica established a new national park around remaining swallowtail habitat after Hurricane Gilbert destroyed most planted Caribbean pines. This allowed natural vegetation to re-establish the rainforest, and the butterfly's host plants rapidly returned.

In the 1980s, UF scientists began studying Homerus Swallowtail ecology with University of the West Indies lepidopterists. Thomas C. Emmel and Jaret C. Daniels later helped establish captive breeding and educational programs in Jamaica to help local conservation efforts. This led to the establishment of John Crow-Blue Mountain National Park, which uses the Homerus Swallowtail as its flagship symbol.

 

Conservation of the Miami Blue

The Miami Blue (Cyclargus thomasi bethunebakeri) is a small, brightly colored butterfly that lives only in Florida. Primarily a coastal species, the Miami Blue inhabits tropical hammocks, beachside scrub and pine rocklands. Its larvae formerly fed on the native Balloon Vine (Cardiospermum corindum) but switched to Gray Nickerbean (Caesalpinia bonduc). Development in coastal areas eliminated the Miami Blue from the south Florida mainland. This alarming decline continued in the Florida Keys. After disappearing for seven years, the species was rediscovered on Bahia Honda Key. Current threats to the remaining tiny population include adult mosquito control spraying, which kills larvae feeding on sprayed host plants; invasive species such as non-native fire ants; herbiciding of roadside habitats; hurricanes; prolonged drought; and human alteration of remaining habitat areas.

In 2002, approximately 50 adult butterflies were flying in Bahia Honda State Park. The same year, scientists established a captive breeding population in Gainesville. The first reintroduction of this species occurred in May 2004 in Everglades National Park, and other sites have received reintroductions after suitable habitats were identified. Over 36,000 Miami Blues have been reared to date at the McGuire Center captive breeding colony.

 

Conservation of the Schaus Swallowtail

The rare Schaus' Swallowtail (Heraclides aristodemus ponceanus Schaus) lives on Elliott Key, one of the few places in south Florida where there is no spraying for mosquito control. Once widespread in south Florida, its population size and distribution were reduced by urbanization of Miami and the Keys, and later by mosquito control spraying with pesticides Dibrom and Baytex.

In captivity Schaus' females lay up to 430 eggs. In nature, predators eat most eggs, and wasps parasitize most larvae. But in the laboratory, researchers can raise most eggs to adults. In 1992, Hurricane Andrew hit south Florida and devastated Schaus' habitat on Elliott Key. This prompted a large-scale captive breeding program. The team bred over 1,500 butterflies in captivity and released them in the Keys and south Florida during 1995-1997.

Success of the new populations is monitored every year. In spring, scientists visit Elliott Key to collect, mark, and release the butterflies. Recapture rates of marked butterflies help estimate population size. The number of individuals flying hovers around several hundred currently because of prolonged drought conditions in south Florida..

 

St. Augustine Hairstreak and Coastal Development

The St. Augustine Hairstreak occurs only in northeast and north central Florida. Colonies are geographically isolated and very small, with only 3-40 adult butterflies normally present. The larvae feed only on Southern Red Cedar trees (Juniperus silicicola). You may see 3-4 males perched on every tree in a colony, waiting for passing females.

Ten years ago, several colonies of the St. Augustine Hairstreak (Mitoura grynea sweadneri) were known from Jacksonville, St. Augustine, and Gulf Coast areas near Cedar Key. Today, colonies remain only inland west of the St. Johns River. The status of this butterfly east of St. Johns River is in question and the original coastal populations may no longer exist.

Coastal development has eliminated many old cedar trees, which led to the demise of this species and continues to be a threat. Also, landscapers often trim cedar tree branches, removing new growth that hosts both eggs and caterpillars. Mulching around tree bases can kill the underground pupae and suppresses wildflowers vital to adult feeding.

Akers Pence (post doctoral research associate, McGuire Center) conducts field and laboratory research on the conservation biology of the St. Augustine Hairstreak. Thomas C. Emmel (McGuire Center) first brought scientific attention to the species' declining status in 1987.