Photuris lugubris Female Fireflies Hunt Males of the Synchronous Firefly Photinus palaciosi (Coleoptera: Lampyridae)

SIMPLE SUMMARY: Adults of most fireflies do not feed, except for the females of several species of Photuris, which eat males of other firefly species. In most cases, female Photuris attract their prey by responding with glows or flashes to the male’s bioluminescent signals, as if they were potential mates. For this reason, female Photuris are also called femmes fatales. In this paper, we provide evidence that the females of Photuris lugubris are femmes fatales of the males of the firefly Photinus palaciosi. We present different types of field observations suggesting that the females of P. lugubris attract males of P. palaciosi by responding to their bioluminescent signals and that, as a consequence, sometimes these are captured and eaten. We demonstrate experimentally that male P. lugubris are not predators of P. palaciosi. We also present experimental evidence that females of P. lugubris mate with multiple males and discuss the potential implications of this observation for the switch between mating and hunting behaviour. P. palaciosi is a firefly that reaches very high densities of flashing males during the reproductive season and that, intermittently, they synchronize their flashes providing a magnificent show that in the last few years has been the focus of tourist activities. Thus, our study also adds to the knowledge on the natural history of a species of economic interest. ABSTRACT: Femmes fatales (Ff) are female fireflies that hunt and feed on the males of other firefly species that they attract by responding with glows or flashes to their bioluminescent signals. Here, we present field observations demonstrating that Photuris lugubris females are Ff of male Photinus palaciosi, a synchronous firefly exploited as a tourist attraction in the mountains of central Mexico. We show that the hunting success of the Ff is low, as observed in previous studies, suggesting that the impact of predation on the prey population is low. We present experimental data showing sex-specific hunting behaviour, since only female P. lugubris fed on P. palaciosi. We also present experimental data showing that at least some female P. lugubris mate multiple times; we discuss the implications of this discovery for the switch between the mating and hunting modes of Ff. We discuss open questions, as well as the possible impact of Ff on tourism focused on synchronous fireflies.