ZANGHI, M. R.*; POISSON, S.; MOOSMAN, P. R. Jr.; CRATSLEY, C. K.; Fitchburg State College: Morphology and flash patterns as potential predictors of flash duration in Photinus fireflies (Coleoptera: Lampyridae).

During courtship, fireflies produce bioluminescent flashes that aid in species recognition and mate location. Flying males produce species-specific patrolling flash patterns, to which perched females respond with bioluminescent flashes after a species-specific time delay. In some single pulse species of Photinus fireflies, females prefer longer duration flashes, while in some multiple pulse Photinus species, females prefer shorter inter-pulse intervals. Additionally, larger species tend to produce longer flash durations. Therefore, we hypothesized that flash duration would vary as a function of both flash pattern (single vs. multiple pulse) and morphology. Male flashes of one double-pulse species, Photinus greeni and two single-pulse species P. ignitus, and P. pyralis were recorded using a photomultiplier tube, and males were weighed, digitally imaged and measured. No single morphological measurement consistently predicted flash duration; however shape index (elytron length divided by body width) was correlated with flash duration in P. pyralis and P. greeni. While longer, thinner males tended to produce longer duration flashes in P. greeni, they produced shorter duration flashes in P. pyralis. We speculate that both flash duration and shape index may be indicators of male condition and that female preferences select for longer duration flashes in P. pyralis, and shorter duration flashes in P. greeni as condition-dependent indicators of mate quality.