The Eglin Uplands Scarab Beetle (Polyphylla pubescens) is a secretive, rarely seen June beetle (subfamily Melolonthinae, family Scarabidae).This species occurs in just two counties on the Florida panhandle (Okaloosa and Walton). It was first collected in 1938, and sightings of individuals have been recorded on fewer than five separate occasions.
Historically, the panhandle has been conducive to evolution of very local, specialized endemic species such as this scarab, partly because rise and fall of ocean water levels during climate shifts in recent historycreated isolated habitats.Polyphylla pubescens lives in inland sandy uplands around Eglin Air Force Base.These beetles have a very localized population, and do not disperse far. Their range is thought to be restricted to 250-1000 square km (about 100-400 square miles).
Female Eglin uplands scarabs possess flight wings, but are thought to be unable to fly.This causes a big constraint to dispersal.Females spend almost their entire lifecycle under the sand.They come above ground only to mate, then burrow back into the sand to lay eggs.The males do fly. Their active period is in June, especially around the time of the new moon. Flights occur especially late afternoon, and sometimes at night.Night-flying males are sometimes attracted to lights.
Eglan upland scarabs are large beetles, between 17.5-19 mm long and 8-9 mm across. The more elusive females are much harder to find, and scientists have collected and studied many more males.Males are slightly smaller and less robust than females, and have more hair.Very little is known about the life history of this rare June beetle.One female kept in captivity laid 25 eggs, but the larvae did not survive, as their food source is unknown.
NatureServe classifies the Eglin uplands scarab as critically imperiled due to its specific habitat requirements and extremely small range. Preservation of the sandy uplands in and around Eglan Airforce Base is required for survival of this species.More research is needed in order to assign a more specific conservation status.
Originally classified into the striped scarabs genus Polyphylla in 1939, Hardy (1975) considered the Eglin uplands scarab unique and moved it into its own, monotypic genus Polylamina.However further morphological and molecular work later revealed that this scarab does, in fact, belong in genus Polyphylla.Skelly (2003) replaced it in Polyphylla and grouped it within this genus into the "pubescens species group" with three putative closest relatives: P. woodruffi (occurs further east on panhandle), P. starkae (peninsular Florida), and P. Donaldsoni (Ohoopee Dunes region of central Georgia). All localized and rare, these species, like P. pubescens, have non-flying females or limited dispersal ability.Skelly (2003) predicts that isolated sand ridges in regions between these species' ranges may harbor other, as yet undiscovered, highly local and specialized members of the pubescens group.
(Cartwright 1939; Coco-Abia 2000; Hardy 1974; Skelley 2003; Skelley 2009; NatureServe 2015)
