Journal of the North Carolina Academy of Science, 124(4), 2008, pp. 139–147 MORPHOLOGY AND BEHAVIOR OF PHAUSIS RETICULATA (BLUE GHOST FIREFLY) JENNIFER E. FRICK-RUPPERT* and JOSHUA J. ROSEN Department of Science and Math, Brevard College, Brevard, NC 28712 Abstract: Phausis reticulata, the Blue Ghost Firefly, is a lampyrid beetle found in the southern Appalachians, observed primarily in May and June. Its luminescence is characterized by a steady glow, in contrast to a species-specific pattern of flashes. It is also characterized by a large degree of sexual dimorphism, with a winged male and paedomorphic, apterous female. Both sexes have light organs. Behavior and habitat of P. reticulata were observed at several locations in the southern Appalachians from 1997 through 2008, most intensively in 2006 and 2007. Information was also gathered from preserved specimens in insect collections. Female anatomy is reported for the first time, and male anatomy is further clarified. Key Words: firefly; lampyrid; Phausis; Appalachians. INTRODUCTION emission varied between individuals, from ‘‘a few The southeastern United States is widely known for seconds to a minute or more.’’ He described the its diversity of lampyrid species (Lloyd 2004); however, paedomorphic female’s green-white glow as originating many of these species are incompletely known and have from four spots on the abdomen in some individuals, not been subject to extensive study. One of these lesser- but six spots in others. The two additional organs known species is Phausis reticulata, the Blue Ghost Firefly. observed in some females are located in the posterior end and are smaller than the other four; Lloyd suggested P. reticulata was first described by Thomas Say in that these may be larval lights temporarily retained into 1825 as Lampyris reticulata (Say 1825). The type adulthood (Lloyd 1965; McDermott 1948). specimen was given to Say by botanist Thomas Nuttall Phausis is one of several genera termed ‘‘glowworm after a trip to the Arkansas Territory. J.L. LeConte fireflies,’’ which are characterized by a burrowing, created the genus Phausis in 1851, with P. reticulata as paedomorphic female who emits light to attract the its first member (LeConte 1851). The genus was last flying male (Lloyd 1971, 1983, 2004; Branham 2003). revised by K.M. Fender in 1966. There are no records in Males of P. reticulata, unlike those of most other the literature of any observation of the eggs, larvae or glowworm fireflies, are luminous. pupae of P. reticulata. P. reticulata is also unusual in that it does not fit In addition to the type locality in Arkansas, P. neatly into the ‘‘signal system’’ classification devised by reticulata was later found in Georgia, Tennessee and Lloyd (1971) to describe communication in fireflies. In Texas (LeConte 1881). K.M. Fender’s specimens were Lloyd’s Signal System I, a stationary female produces a from western North Carolina (Avery County; Cherokee species-specific photic signal to attract the flying male. County), eastern Tennessee (Morgan County), and In Signal System II, the flying male emits a photic signal central Tennessee (Smith County); he reports that the to which the female responds after a brief delay; photic distribution of P. reticulata is centered in the Black signals and delay length are species-specific (Lloyd 1971; Mountains of western North Carolina (Fender 1966). Branham et al. 2003). Lloyd suggested a ‘‘transitional’’ J.E. Lloyd (1965) also found P. reticulata in both system for P. reticulata because females glow to attract western North Carolina (Mt. Pisgah, Buncombe Coun- males (Signal System I) and also illuminate their lights ty) and in eastern Tennessee (Great Smoky Mountains when a male passes overhead (Signal System II) (Lloyd National Park, Sevier County). Lloyd later wrote the 1965, 1966, 1971). Lloyd later replaced the signal system species could be found in ‘‘scattered localities across paradigm with a broader concept that focused on photic North America to Oklahoma, but can be seen in signals, habitat, mating season and other factors (Lloyd abundance in the Appalachian Mountains’’ (Lloyd 2004). 1983; Branham et al. 2003), and his hypothesis that J.E. Lloyd (1965), in the only record of field research signal system II originated from signal system I has not involving P. reticulata, reported that males flew ‘‘in a been supported (Branham et al. 2003). variety of fashions’’; some rapidly, others more slowly. The purpose of this study was to elucidate the Males emitted a bright green glow; the period of light structure of both males and females of Phausis reticulata and to study their behavior. While it was known that the * e-mail: [email protected] females were larviform, their specific anatomy was 139 140 JOURNAL OF THE NORTH CAROLINA ACADEMY OF SCIENCE 124(4) unreported. We compared preferred habitat, seasonal- proximity of water bodies. Precipitation and moonlight ity, nightly activity levels, and density of both males and levels were recorded during site visits in 2006 and 2007. females and hypothesized that since luminescence is Air temperature, soil temperature, relative humidity, air used in sexual signaling, males and females would pressure, rainfall, wind speed, and wind direction were respond to each other and to other light sources prior to recorded in 2006 in DuPont State Forest on two days mating. with different weather conditions to evaluate their effect on P. reticulata behavior. Air and ground temperatures were recorded in 2008 in Balsam Grove. METHODS Behavioral observations of P. reticulata males includ- Several field sites in four states (North Carolina, ed flight speed and height from the ground, density and Tennessee, Georgia and South Carolina) across the pattern of distribution, time of emergence and peak southern Appalachians were utilized. Four sites in NC activity. Observations of the non-flighted females included DuPont State Forest, a 4,200-hectare tract of concentrated on distribution, reaction to stimulus and preserved forest in southeastern Transylvania County intensity/duration of light emission. Collected specimens and southwestern Henderson County at an elevation of were restrained in transparent plastic containers. Reac- 730 m (at the study site); Pink Beds Picnic Area in tions of both males and females to bursts of white, red, Pisgah National Forest, a popular recreational area of and blue light and physical disturbance were recorded. about 400 hectares at 1,000 m elevation in northeastern Two females (2006, DuPont State Forest) were placed Transylvania County; Sherwood Forest, a private 400- separately in small, shallow, transparent containers hectare community in Cedar Mountain, southeastern nestled into the leaf litter to experimentally observe Transylvania County, 880 m elevation; and a private, male/female interaction. These females were later placed 32-hectare tract in Balsam Grove in northern Transyl- directly into the leaf litter. Mating under natural vania County at 915 m. conditions was also observed (DuPont State Forest Two sites in TN were located in Great Smoky and Balsam Grove). Four males (2006, DuPont State Mountains National Park (GSMNP) and both were at Forest) were placed into small plastic containers and 580 m elevation: Porters Creek Trail (Sevier County), kept in the dark at constant temperature overnight in located in the Greenbrier area of the park, and Middle order to evaluate circadian rhythms. They were ob- Prong Trail (Blount County) in the Tremont area of the served every few hours. park. Warwoman Dell Recreation Area in GA falls In addition to specimens collected at the different field within the Chattahoochee National Forest in central sites, we also examined those in the insect collections of Rabun County near Clayton at 500 m elevation. Asbury Brevard College, Clemson University, University of Hills in SC, examined in 2007, is a 730-hetare camp and Georgia, and North Carolina State University. We retreat center at 365 m elevation located in northwestern accessed the database of the All Taxa Biodiversity Greenville County near Cleveland. Cleveland is host to Inventory for the Great Smoky Mountains National an annual viewing event of the Blue Ghosts on Park and downloaded its information on collection 50 hectares of private land owned by Mr. Don Lewis locations, but were not shipped specimens. The insect and is located at 307 m elevation. Lloyd’s collection site collections of Virginia Tech, Virginia Museum of at the base of Mt. Pisgah in Buncombe County, NC, Natural History and University of Tennessee-Knoxville specifically the trailhead at the parking area, was visited did not have any specimens of P. reticulata. on 8 June 2008. Microscopic examination of specimens was per- Initial observations and identification of P. reticulata formed using a Wild-M5 microscope and drawings were began in May and June of 1997 in Balsam Grove, NC. completed with the aid of a camera lucida. A Sony One of us (J. Frick-Ruppert) collected and observed High-Definition-Video HCR-HC3 Handycam Cam- males and females, recording information on their corder mounted on a Motic SMZ-168 or a Nikon habitat preferences, seasonality, nightly activity levels, Coolpix 5,000 digital camera provided photographic and density each year between 1997 and 2008. In 2006, documentation. when J. Rosen joined the study, we added the new field sites, and in 2007, concentrated in DuPont State Forest RESULTS where P. reticulata had been observed in abundance during 2006: a small enclave opposite the Triple Falls Morphology Trailhead, the forest surrounding the Buck Forest Fender (1966) is the basis for our identification of Parking Area, and Buck Forest Road. Phausis reticulata males. Males range from 5.0–8.5 mm Observations of habitat at each field site included total body length (Table 1) and are approximately 1 mm dominant plant species, amount of vegetative cover, leaf in width. The ratio of length to width of the thorax is litter levels, prominent topographical features and the 2.0:1.5 (Fig.