Bringing Light to the Lives of the Shadow Ghosts, Phausis inaccensa (Coleoptera: Lampyridae)

Over 13 seasons, from 1992 to 2016, field studies detailing the life habits of Phausis inaccensa LeConte were carried out primarily in Mississippi and Tennessee with additional data from Arkansas, Pennsylvania, North Carolina, and Minnesota. From late March to May in the southern states, ≈45 minutes after sunset, apterous, neotenic females emerge from their daytime shelters in the leaf litter, glow from two spots at the end of their upturned abdomens, and attract flying, lanternless males. Signaling females, often in loose groupings of three to four, attract multiple males that land near (60 mm, SD 15) but not directly on them. Male activity was greatest from 30 to 60 minutes after sunset, and ended by two hours past sunset. Unmated females displayed longer (from 90 minutes to all night) than the mated females, which typically displayed for a shorter time. Eighty percent of the females signaled and mated on a single night. Mating durations were brief, averaging eight minutes when one male was present, but significantly longer (12–45 minutes) when more than one male was present. In captivity, both males and females mated multiple times. More than 90% of the males and 70% of the females were active during the three-week period that equaled about 450–500 modified growing degree days Fahrenheit. Northern populations showed a different seasonality, but similar habits. Females lived an average of 14 days in captivity, oviposited clutches of 20–30 round pale eggs, 0.5 mm diameter, and exhibited maternal care and guarding of their eggs until their death six to nine days after oviposition. Larvae, 1.57 mm, emerged in 34–37 days. We compare these observations with similar and often sympatric Phausis reticulata Say, the Blue Ghost firefly, whose males glow during their flights in search of females.