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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.

Bioluminescence is found across the tree of life and has many functions. Yet we understand very little about its timing and origins, particularly as a predator avoidance strategy. Understanding the timing between bioluminescence and predator origins has yet to be examined and can help elucidate the evolution of this ecologically important aposematic signal. Using the most prevalent bioluminescent group, fireflies, where bioluminescence primarily functions as aposematic and sexual signals, the timing for the origins of both potential predators of fireflies and bioluminescence is explored. Divergence time estimations were performed using genomic-scale phylogenetic reconstructions, and multiple fossil calibration points, allowing for a robust estimate for the origin of lampyrid bioluminescence as a terrestrial and as an aerial signal. Our results recover the origins of terrestrial beetle bioluminescence at 141.17 (122.63–161.17) mya and firefly aerial bioluminescence at 133.18 (117.86–152.47) mya with a large dataset focused on Lampyridae; and terrestrial bioluminescence as 148.03 (130.12–166.80) mya, with the age of aerial bioluminescence at 104.97 (99.00–120.90) mya with a complementary broad Elateroidea dataset. These ages predate the origins of all known extant aerial predators (i.e., bats and birds) and support the much older terrestrial predators (assassin bugs, frogs, ground beetles, lizards, snakes, hunting spiders, and harvestmen) as the most likely drivers of terrestrial bioluminescence in beetles, and sexual signaling likely being the original function in aerial fireflies.

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&nbsp, afterpotential&nbsp, 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.

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).

Fireflies (Lampyridae Rafinesque) are a diverse family of beetles which exhibit an array of morphologies including varying antennal and photic organ features. Due in part to their morphological diversity, the classification within the Lampyridae has long been in flux. Here we use an anchored hybrid enrichment approach to reconstruct the most extensive molecular phylogeny of Lampyridae to date (436 loci and 98 taxa) and use this phylogeny to evaluate the higher-level classification of the group. None of the currently recognized subfamilies were recovered as monophyletic with high support. We propose several classification changes supported by both phylogenetic and morphological evidence: 1) Pollaclasis Newman, Vestini McDermott (incl. Vesta Laporte, Dodacles Olivier, Dryptelytra Laporte, and Ledocas Olivier), Photoctus McDermott, and Araucariocladus Silveira & Mermudes are transferred to Lampyridae incertae sedis, 2) Psilocladinae Mcdermott, 1964status novum is reestablished for the genus Psilocladus Blanchard, 3) Lamprohizini Kazantsev, 2010 is elevated to Lamprohizinae Kazantsev, 2010status novum and Phausis LeConte is transferred to Lamprohizinae, 4) Memoan Silveira and Mermudes is transferred to Amydetinae Olivier, and 5) Scissicauda McDermott is transferred to Lampyrinae Rafinesque.

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.

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., eLife digest Glowing fireflies dancing in the dark are one of the most enchanting sights of a warm summer night. Their light signals are ‘love messages’ that help the insects find a mate – yet, they also warn a potential predator that these beetles have powerful chemical defenses. The light comes from a specialized organ of the firefly where a small molecule, luciferin, is broken down by the enzyme luciferase. Fireflies are an ancient group, with the common ancestor of the two main lineages originating over 100 million years ago. But fireflies are not the only insects that produce light: certain click beetles are also bioluminescent. Fireflies and click beetles are closely related, and they both use identical luciferin and similar luciferases to create light. This would suggest that bioluminescence was already present in the common ancestor of the two families. However, the specialized organs in which the chemical reactions take place are entirely different, which would indicate that the ability to produce light arose independently in each group. Here, Fallon, Lower et al. try to resolve this discrepancy and to find out how many times bioluminescence evolved in beetles. This required using cutting-edge DNA sequencing to carefully piece together the genomes of two species of fireflies (Photinus pyralis and Aquatica lateralis) and one species of click beetle (Ignelater luminosus). The genetic analysis revealed that, in all species, the genes for luciferases were very similar to the genetic sequences around them, which code for proteins that break down fat. This indicates that the ancestral luciferase arose from one of these metabolic genes getting duplicated, and then one of the copies evolving a new role. However, the genes for luciferase were very different between the fireflies and the click beetles. Further analyses suggested that bioluminescence evolved at least twice: once in an ancestor of fireflies, and once in the ancestor of the bioluminescent click beetles. More results came from the reconstituted genomes. For example, Fallon, Lower et al. identified the genes ‘turned on’ in the bioluminescent organ of the fireflies. This made it possible to list genes that may be involved in creating luciferin, and enable flies to grow brightly for long periods. In addition, the genetic information yielded sequences from bacteria that likely live inside firefly cells, and which may participate in the light-making process or the production of potent chemical defenses. Better genetic knowledge of beetle bioluminescence could bring new advances for both insects and humans. It may help researchers find and design better light-emitting molecules useful to track and quantify proteins of interest in a cell. Ultimately, it would allow a detailed understanding of firefly populations around the world, which could contribute to firefly ecotourism and help to protect these glowing insects from increasing environmental threats.

Among insects, opsin copy number variation has been shown to be quite diverse. However, within the beetles, very little work on opsins has been conducted. Here, we look at the visual system of fireflies (Coleoptera: Lampyridae), which offer an elegant system in which to study visual evolution as it relates to their behavior and broader ecology. They are the best-known case of a terrestrial organism that communicates through the use bioluminescence. The molecular basis for this communication is relatively simple: one gene family (opsins) controls the detection of the signal, and one gene family (luciferase) controls the production of the signal. We use a transcriptomic approach to sample for and investigate opsin evolution in fireflies. We also use a phylogenetic estimate of Lampyridae to examine the evolution and ancestral modality of adult courtship communication. We find evidence for only two expressed opsin classes in each of the nine firefly species studied, one in the ultraviolet-sensitive and one in the long-wavelength-sensitive areas of the visible spectrum. Bioluminescent communication in adults is not optimized to be present ancestrally, and was gained two times with six subsequent losses. Despite the need for most adult fireflies to respond to a clearly sexual and colorful visual signal (bioluminescence) to maximize fitness, their visual system is relatively simple, and does not match the trend for opsin duplication found in other insect groups.

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.

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.

Modern gold deportment studies include physical, chemical and mineralogical assessments, combined to obtain a full understanding of the nature and variability of gold in a resource. The objective is to provide information which will allow cost effective and practical processing by informing decisions regarding resource evaluation, mining method and extraction process optimization. The distribution of gold, based on speciation, grain size and mode of occurrence (liberation, exposure, and mineral association) is quantitatively determined by means of automated Scanning Electron Microscopic Techniques (QEMSCAN/MLA). Furthermore, general mineralogical characterization is undertaken in order to characterize the gangue components; with special emphasis on deleterious characteristics of the ore (e.g. cyanide consumers such as secondary Cu-species, preg-robbers/borrowers, passivation due to Sb-minerals or As-minerals and oxygen consumers such as pyrrhotite/marcasite). Predictions based on the mineralogical observations are confirmed by physical and chemical testwork. These include grading analyses, gravity separation, direct cyanidation, and diagnostic (sequential) leach tests.