Beetle bioluminescence outshines extant aerial predators.

We understand very little about the timing and origins of bioluminescence, particularly as a predator avoidance strategy. Understanding the timing of its origins, however, can help elucidate the evolution of this ecologically important signal. Using fireflies, a prevalent bioluminescent group where bioluminescence primarily functions as aposematic and sexual signals, we explore the origins of this signal in the context of their potential predators. Divergence time estimations were performed using genomic-scale datasets providing a robust estimate for the origin of firefly bioluminescence as both a terrestrial and as an aerial signal. Our results recover the origin of terrestrial beetle bioluminescence at 141.17 (122.63-161.17) Ma and firefly aerial bioluminescence at 133.18 (117.86-152.47) Ma using a large dataset focused on Lampyridae; and terrestrial bioluminescence at 148.03 (130.12-166.80) Ma, with the age of aerial bioluminescence at 104.97 (99.00-120.90) Ma using a complementary Elateroidea dataset. These ages pre-date the origins of all known extant aerial predators (i.e. bats and birds) and support much older terrestrial predators (assassin bugs, frogs, ground beetles, lizards, snakes, hunting spiders and harvestmen) as the drivers of terrestrial bioluminescence in beetles. These ages also support the hypothesis that sexual signalling was probably the original function of this signal in aerial fireflies.

Total evidence phylogeny and the evolution of adult bioluminescence in fireflies (Coleoptera: Lampyridae).

Fireflies are some of the most captivating organisms on the planet. They have a rich history as subjects of scientific study, especially in relation to their bioluminescent behavior. Yet, the phylogenetic relationships of fireflies are still poorly understood. Here, we present the first total evidence approach to reconstruct lampyrid phylogeny using both a molecular matrix from six loci and an extensive morphological matrix. Using this phylogeny we test the hypothesis that adult bioluminescence evolved after the origin of the firefly clade. The ancestral state of adult bioluminescence is recovered as non-bioluminescent with one to six gains and five to ten subsequent losses. The monophyly of the family, as well as the subfamilies is also tested. Ototretinae, Cyphonocerinae, Luciolinae (incl. Pristolycus), Amydetinae, "cheguevarinae" sensu Jeng 2008, and Photurinae are highly supported as monophyletic. With the exception of four taxa, Lampyrinae is also recovered as monophyletic with high support. Based on phylogenetic and morphological data Lamprohiza, Phausis, and Lamprigera are transferred to Lampyridae incertae sedis.

Molecular Evolution of Phototransduction Pathway Genes in Nocturnal and Diurnal Fireflies (Coleoptera: Lampyridae).

Most organisms are dependent on sensory cues from their environment for survival and reproduction. Fireflies (Coleoptera: Lampyridae) represent an ideal system for studying sensory niche adaptation due to many species relying on bioluminescent communication; as well as a diversity of ecologies. Here; using transcriptomics; we examine the phototransduction pathway in this non-model organism; and provide some of the first evidence for positive selection in the phototransduction pathway beyond opsins in beetles. Evidence for gene duplications within Lampyridae are found in inactivation no afterpotential C and inactivation no afterpotential D. We also find strong support for positive selection in arrestin-2; inactivation no afterpotential D; and transient receptor potential-like; with weak support for positive selection in guanine nucleotide-binding protein G(q) subunit alpha and neither inactivation nor afterpotential C. Taken with other recent work in flies; butterflies; and moths; this represents an exciting new avenue of study as we seek to further understand diversification and constraint on the phototransduction pathway in light of organism ecology.

Type designations for fireflies (Coleoptera: Lampyridae) of the Biologia Centrali Americana Gorham, 1881 housed in the Natural History Museum, London.

The Biologia Centrali Americana (B.C.A.) is comprised of eight volumes that deal specifically with Coleoptera. These volumes were split into 18 parts and were published between 1879 and 1911. The family Lampyridae was treated in two parts, the main text (1881) with a supplement (1884). Within volume three, part 2, Gorham lists ~90 species in 14 genera, not including the Phengodini subfamily. Of these, Gorham provided original descriptions for 37 species. During recent research visits (2018 and 2020) the authors were able to study material pertinent to the B.C.A. We were able to confidently designate holotypes, lectotypes, and paralectotypes following ICZN articles 73.1 and 74.1 within these species. Two species described by Gorham (1881) are not treated here. Phaenolis nirgricollis was located with a single specimen, already designate as the holotype. Two female syntypes of Photinus consanguineous were located, however Oliver (1907) synonymized these females with Photinus pyralis. These designations contribute to a larger taxonomic effort to stabilize the nomenclature of this group. The species described in the supplement will be treated in a future work. Subfamilies are listed according to Martin et al. (2019) and genera/species within each subfamily are listed according to the order in Gorham (1881).

Two new species of coastal Atyphella Olliff (Lampyridae: Luciolinae).

Additional work on the islands of Vanuatu has improved our understanding of the actual diversity of South Pacific coastal fireflies. Prior to recent fieldwork in Vanuatu, the only known lampyrid from Vanuatu was Atyphella aphrogeneia (Ballantyne), a coastal species also found in Papua New Guinea. After further examination, we determined that specimens from Vanuatu formerly classified as Atyphella aphrogeneia actually belong to an undescribed species. New species, Atyphella maritimus Saxton and Powell and Atyphella marigenous Saxton and Bybee, are described from specimens collected in Vanuatu. An updated key for coastal Atyphella in the South Pacific is provided.

Type designations for sap beetles in the subfamily Carpophilinae Erichson (Coleoptera: Nitidulidae) housed in the Natural History Museum, London.

The subfamily Carpophilinae, in particular the genus Carpophilus Stephens, represents one of the most speciose lineages within Nitidulidae. The subfamily was first recognized by Erichson (1843) in a much broader sense, including what is now the Cillaeinae. According to Kirejtshuk (2008), there are seven genera and 13 subgenera within Carpophilinae. To date, however, no comprehensive tribal or generic phylogenetic reconstructions have been published for the subfamily. This work constitutes a preliminary stage of a larger project that will address the subfamily in a rigorous taxonomic and systematic framework. A stable taxonomic foundation for Carpophilus species and other Carpophilinae taxa is needed to ensure the validity of future work in the subfamily. Herein we designate lectotypes and paralectotypes and confirm holotypes for 14 species of carpophiline sap beetles following ICZN (1999) articles 73.1 and 74.1.

Firefly genomes illuminate parallel origins of bioluminescence in beetles.

Fireflies and their luminous courtships have inspired centuries of scientific study. Today firefly luciferase is widely used in biotechnology, but the evolutionary origin of bioluminescence within beetles remains unclear. To shed light on this long-standing question, we sequenced the genomes of two firefly species that diverged over 100 million-years-ago: the North American Photinus pyralis and Japanese Aquatica lateralis. To compare bioluminescent origins, we also sequenced the genome of a related click beetle, the Caribbean Ignelater luminosus, with bioluminescent biochemistry near-identical to fireflies, but anatomically unique light organs, suggesting the intriguing hypothesis of parallel gains of bioluminescence. Our analyses support independent gains of bioluminescence in fireflies and click beetles, and provide new insights into the genes, chemical defenses, and symbionts that evolved alongside their luminous lifestyle.

New record of a phoretic flea associated with earwigs (Dermaptera, Arixeniidae) and a redescription of the bat flea Lagaropsylla signata (Siphonaptera, Ischnopsyllidae).

Lagaropsylla signata (Wahlgren, 1903), previously known only from the Island of Java, Indonesia is redescribed and reported for the first time in Deer Cave, Gunung Mulu National Park, Sarawak, Malaysia (west coast of Borneo). Many were found clinging to the earwig Arixenia esau Jordan, 1909. A similar account of a phoretic flea (Lagaropsylla turba Smit, 1958) on the same species of cave-dwelling earwig has been reported in peninsular Malaysia in a well-documented association with the hairless naked bulldog bat, Cheiromeles torquatus Horsfield, 1824. The association of Lagaropsylla signata with Arixenia esau is parallel to the evolution and co-existence with bats in Deer Cave just as in the case of Lagaropsylla turba, Arixenia esau, and Cheiromeles torquatus. The evidence suggests that Lagaropsylla turba and Lagaropsylla signata are obligate phoretic parasites whose survival depends on Arixenia esau to access a bat host. Arixenia esau is reported for the first time in Deer Cave and the occurrence of Lagaropsylla signata on the island of Borneo represented a new record, previously being found only on the island of Java. Images of Lagaropsylla signata attached to Arixenia esau are provided. Xeniaria jacobsoni (Burr, 1912), often associated with Arixenia esau in other geographical areas, was not present in the material examined from Deer Cave. The natural history of the earwig genera Arixenia Jordan, 1909 and Xeniaria Maa, 1974 are discussed and summarized relative to their associations with phoretic fleas and their bat hosts.

Overcoming the loss of blue sensitivity through opsin duplication in the largest animal group, beetles.

Opsin proteins are fundamental components of animal vision whose structure largely determines the sensitivity of visual pigments to different wavelengths of light. Surprisingly little is known about opsin evolution in beetles, even though they are the most species rich animal group on Earth and exhibit considerable variation in visual system sensitivities. We reveal the patterns of opsin evolution across 62 beetle species and relatives. Our results show that the major insect opsin class (SW) that typically confers sensitivity to "blue" wavelengths was lost ~300 million years ago, before the origin of modern beetles. We propose that UV and LW opsin gene duplications have restored the potential for trichromacy (three separate channels for colour vision) in beetles up to 12 times and more specifically, duplications within the UV opsin class have likely led to the restoration of "blue" sensitivity up to 10 times. This finding reveals unexpected plasticity within the insect visual system and highlights its remarkable ability to evolve and adapt to the available light and visual cues present in the environment.