Natural history and flash repertoire of the synchronous firefly Photinus carolinus (Coleoptera: Lampyridae) in the Great Smoky Mountains National Park

Abstract

The synchronous firefly Photinus carolinus (Green) of the moist cove hardwood forests of the Great Smoky Mountains National Park attracts much public attention during its spectacular month-long mating display known as The Light Show. In previous studies flash synchrony among P. carolinus males has been investigated, but little is known about its natural history and mating behavior. This study provides additional information on the habits, flash signal variation, mating strategies, predation and historical records of P. carolinus. The polyandrous females remate throughout their approximately 3-week adult lifespan, laying successive clutches of eggs. While stationary females generally respond to male courtship signals with a receptive doublet flash signal, they also produce a rhythmic flash while walking, and can revert back to the receptive state. In this protandrous species, the average number of flashes per flash train in male courtship signals increases after females have emerged. I describe pseudo-female male flashes and group chaos flashing associated with mating clusters as well as conditions causing distress flashing in both sexes. With a backdrop of changing habitat and increasing human pressure, observations taken from the past 18 years and over 1000 h spent in the field additionally describe male guarding of a female pupa, mate guarding via prolonged copulation, common predator and phorid infestation challenges for this firefly.