MIAMI (AP) - Two butterfly species historically found in South Florida are likely now extinct, U.S. wildlife officials said Monday.
After several years of studying imperiled butterflies, the U.S. Fish and Wildlife Service believes the Zestos (Epargyreus zestos oberon) and rockland grass (Hesperia meskei pinocayo) skippers are likely extinct.
The Zestos skipper was last observed at the Key West Tropical Forest and Botanical Garden on Stock Island in 2004. That butterfly had not been observed on mainland Florida for decades. The rockland grass skipper was last observed at Everglades National Park in 2000, wildlife officials said in a statement.
The Zestos skipper wasn't considered imperiled globally because it is found throughout the Bahamas and eastern Antilles. It was only recently discovered that the Zestos skipper in Florida was a distinct subspecies, but it was gone before conservationists could protect it.
The rockland grass skipper was also believed extinct in the 1980s until it was briefly rediscovered on Big Pine Key in 1999. But it disappeared again before it could be saved, according to wildlife officials.
Butterfly scientists and activists have done extensive surveys in recent years in public conservation lands throughout South Florida and the Keys to determine the status of imperiled butterflies. Several wildlife groups have united to monitor the federally endangered Schaus swallowtail and Miami blue butterflies in the Florida Keys.
The Miami blue butterfly was believed extinct after Hurricane Andrew, until a small population was discovered seven years later in a Keys state park.
That population has since disappeared, despite a University of Florida breeding program that released 30,000 of the butterflies in the Upper Keys to try to expand its range. Now Miami blues are found only on a remote island within the Florida Keys National Wildlife Refuge.
Officials attribute declining butterfly populations to diminishing habitats, poaching, insecticides and threats from predators such as fire ants.
"We're saddened by the loss of the Zestos and rockland grass skippers and hope their loss serves as a wake-up call that we really need to intensify our efforts to save other imperiled butterflies in South Florida." said Larry Williams, the wildlife service's Florida State Supervisor for Ecological Services.
A new state grant will tap members of the North American Butterfly Association to help monitor the population levels of other imperiled South Florida butterfly species.