Oculogryphus chenghoiyanae sp. n. (Coleoptera, Lampyridae): a new ototretine firefly from Hong Kong with descriptions of its bioluminescent behavior and ultraviolet-induced fluorescence in females

Abstract

The first Oculogryphus species with associated males and female was found in Hong Kong and is described as new: O. chenghoiyanae sp. n. Adults of both sexes were collected live in the field and their bioluminescent behavior is reported for the first time in the genus. The captive males emit weak and continuous light from a pair of light spots on abdominal ventrite 6 or do so when disturbed. The larviform (highly paedomorphic) females can glow brightly from a pair of light-emitting organs on the abdomen. The females of Oculogryphus and Stenocladius are to date the only documented representatives of paedomorphism in ototretine fireflies. The finding is consistent with the evidence from male morphology and bioluminescent behavior, supporting the close relationship between the two genera. A key to the Oculogryphus species is provided. The Oculogryphus females can fluoresce with a blue-green light through the whole body under ultraviolet illumination, a phenomenon reported in the Lampyridae for the first time. The co-occurrence of bioluminescence and fluorescence is rare in terrestrial ecosystems, previously known only in some millipedes (Diplopoda). The fluorescence and bioluminescence abilities of Oculogryphus females are functionally independent: abdominal light-emitting organs producing bright yellowish green light while the body wall fluoresces with blue-green light. In contrast, fluorescence and bioluminescence in millipedes are biochemically linked, like in some jellyfish (Cnidaria: Medusozoa).

Fluorescence in Fireflies (Coleoptera: Lampyridae): Using Sentinel Prey to Investigate a Possible Aposematic Signal

“…Adults of several firefly species are known to display externally visible, UV-induced fluorescent markings on various body regions, as evidenced by our study and those of Metcalf (1943), Sannasi (1970), Cicero (2008), Deheyn and Ballantyne (2009), as well as Yiu and Jeng (2018). Also fluorescence has been observed in diurnal and nocturnal species that differ remarkably in range, behavior, and life history.…”

“…Fluorescence has been found in the light producing organs of the firefly Bourgeoisia hypocrita (Olivier) (Coleoptera: Lampyridae), as well as in dorsal and ventral markings (Deheyn & Ballantyne 2009). Yiu and Jeng (2018) recently described whole-body blue-green fluorescence in the neotenic, flightless females of a newly described nocturnal lampyrid from Hong Kong, Oculogryphus chenghoiyanae Yiu & Jeng (Coleoptera: Lampyridae). Wiesenborn (2011) reported representatives of several insect orders that show blue fluorescence (emission maximum at 420 nm) associated with resilin, a structural protein providing elasticity.…”

“…Fluorescence has been observed in fireflies that differ remarkably in their range, behavior, and life history, and several alternative explanations for firefly fluorescence are possible (Yiu & Jeng 2018). First, it is possible that firefly fluorescence has no adaptive value and is merely correlated with other features of body pigmentation.…”

“…Examining preserved museum specimens with a UV light, Metcalf noted red fluorescence in 43 different lampyrid taxa, while it was lacking in related beetles he examined in the clades Phengodidae, Cantharidae, and Lycidae. Fluorescence in specific body regions has subsequently been reported in other firefly species (Sannasi 1970;Cicero 2008;Deheyn & Ballantyne 2009;Yiu & Jeng 2018), yet its function remains unexamined. In contrast to bioluminescence, fluorescence may serve as a passive warning signal that is useful in dim or daylight conditions.…”

A Description and Examination of Fluorescence in Nine North American Firefly Species (Coleoptera: Lampyridae)

“…Some fireflies are also known to display bright fluorescence [12][13][14][15][16][17]. Metcalf in 1943 first reported a red UV fluorescent pigment lampyrine in the firefly Photinus marginellus LeConte.…”