The origin of photic behavior and the evolution of sexual communication in fireflies (Coleoptera: Lampyridae)

Abstract

Through a phylogenetic analysis using adult morphological characters, we show that the origin of bioluminescence in cantharoid beetles appears to predate the origin of the family Lampyridae. The ability to produce and emit photic signals was first gained by larvae and appears to function as an aposematic warning display; it was subsequently gained in adults and is used as a sexual signal. Our analysis also suggests that while pheromonal sexual signals are used basally in the family, they are used in conjunction with and then subsequently replaced by photic signals in some lampyrid lineages. Both photic signals and the photic organs used to produce them have become greatly elaborated in the fireflies that no longer employ pheromonal sexual signals. In addition, the ability to produce a flashed sexual signal appears to have arisen at least three times in the family Lampyridae. Convergent evolution is also evident in a number of adult male photic organ morphologies. Further, we recommend that individual signal system components be compared rather than overall signal system complexity. The use of this strategy may allow one to recognize and better interpret adaptive correlations despite convergence or loss. We demonstrate that phylogenetic analysis is a powerful tool even for rapidly evolving traits.

Structure and function of the eversible glands of the aquatic firefly Luciola leii (Coleoptera: Lampyridae)

“…In response to both aquatic and terrestrial invertebrate and vertebrate predation, L. leii larvae have evolved a multivariate suite, or syndrome, of defensive characters. Although McDermott (1964) and Sivinski (1981) hypothesized that luminescence alone first evolved as an aposematic signal, a recent phylogenetic study provides insight into why conspicuousness and chemical defence may have evolved in tandem (Branham and Wenzel 2003). In the Branham and Wenzel scheme, a younger grade of cantharoids, the likely firefly ancestor is thought to have evolved both distasteful and luminescent species, serving as models in many mimicry rings (Moore and Brown 1981).…”

“…The lampyrids probably inherited the positive covariance of chemical and luminescent traits. Within the radiation of the Lampyridae, Luciola is one of the most derived genera (Branham and Wenzel 2003). Its aquatic members appear to have secondarily colonized aquatic habitats, a shift which may explain some of the chemical characteristics, such as low aquatic diffusion coefficients of the glandular secretion, as the legacy of their terrestrial ancestors.…”

Shunning the night to elude the hunter: diurnal fireflies and the “femmes fatales”

“…We fully realize that in making such an argument we are being speculative. Phyletic relationships, while well worked out for the Lepidoptera, are still subject to some uncertainties as regards the various subgroups of fireflies (Branham & Wenzel 2002).…”

“…Their light organs are vestigial, providing evidence that Lucidota evolved from nocturnal ancestors. So far as known, their mating rituals proceed in daytime, without involvement of the light organs (Branham and Archangelsky 2000;Branham and Wenzel 2002;Lloyd 1972). Nothing was known about the defensive chemistry of Lucidota species, although it seemed likely that they produced LBGs, given that the genus Lucidota belongs to the same subfamily (Lampyrinae) and tribe (Photinini) as Photinus.…”

Structure and function of the eversible organs of several genera of larval firefly (Coleoptera: Lampyridae)

“…Adults of most firefly species glow or flash, but bioluminescence in the larvae is common to all species without exception. The larvae glow when stationary, crawling or when disturbed (Christensen and Carlson 1982;Sivinski 1981;Branham and Wenzel 2003). Their pulses of light represent a conspicuous signal that has been shown to function as an aposematic defence, which warns predators of distastefulness and unprofitability (Underwood et al 1997;De Cock and Matthysen 1999 quite like the freshwater limpet Latia neritoides does with its luminescent mucus when attacked (Meyer-Rochow and Moore 1988).…”