Illuminating Firefly Diversity: Trends, Threats and Conservation Strategies.

Fireflies are a diverse group of bioluminescent beetles belonging to the family Lampyridae. Recent research on their diversity, evolution, behavior and conservation has greatly advanced our scientific understanding of these charismatic insects. In this review, we first summarize new discoveries about their taxonomic and ecological diversity, then focus on recent endeavors to identify and protect threatened fireflies around the world. We outline the main threats linked to recent population declines (habitat loss and degradation, light pollution, pesticide overuse, climate change and tourism) and describe relevant risk factors that predict which species will be particularly vulnerable to these threats. Although global coordination of firefly conservation efforts has begun only recently, considerable progress has already been made. We describe work by the IUCN SSC Firefly Specialist Group to identify species currently facing elevated extinction risks and to devise conservation strategies to protect them. To date, IUCN Red List assessments have been completed for 150 firefly taxa, about 20% of which face heightened extinction risks. The conservation status for many species has yet to be determined due to insufficient information, although targeted surveys and community science projects have contributed valuable new data. Finally, we highlight some examples of successful firefly habitat protection and restoration efforts, and we use the framework of the IUCN SSC Species Conservation Cycle to point out high-priority actions for future firefly conservation efforts.

Two centuries of biodiversity discovery and loss in Singapore.

There is an urgent need for reliable data on the impacts of deforestation on tropical biodiversity. The city-state of Singapore has one of the most detailed biodiversity records in the tropics, dating back to the turn of the 19th century. In 1819, Singapore was almost entirely covered in primary forest, but this has since been largely cleared. We compiled more than 200 y of records for 10 major taxonomic groups in Singapore (>50,000 individual records; >3,000 species), and we estimated extinction rates using recently developed and novel statistical models that account for "dark extinctions," i.e., extinctions of undiscovered species. The estimated overall extinction rate was 37% (95% CI [31 to 42%]). Extrapolating our Singapore observations to a future business-as-usual deforestation scenario for Southeast Asia suggests that 18% (95% CI [16 to 22%]) of species will be lost regionally by 2100. Our extinction estimates for Singapore and Southeast Asia are a factor of two lower than previous estimates that also attempted to account for dark extinctions. However, we caution that particular groups such as large mammals, forest-dependent birds, orchids, and butterflies are disproportionately vulnerable.

Convergence of dominance and neglect in flying insect diversity.

Most of arthropod biodiversity is unknown to science. Consequently, it has been unclear whether insect communities around the world are dominated by the same or different taxa. This question can be answered through standardized sampling of biodiversity followed by estimation of species diversity and community composition with DNA barcodes. Here this approach is applied to flying insects sampled by 39 Malaise traps placed in five biogeographic regions, eight countries and numerous habitats (>225,000 specimens belonging to >25,000 species in 458 families). We find that 20 insect families (10 belonging to Diptera) account for >50% of local species diversity regardless of clade age, continent, climatic region and habitat type. Consistent differences in family-level dominance explain two-thirds of variation in community composition despite massive levels of species turnover, with most species (>97%) in the top 20 families encountered at a single site only. Alarmingly, the same families that dominate insect diversity are 'dark taxa' in that they suffer from extreme taxonomic neglect, with little signs of increasing activities in recent years. Taxonomic neglect tends to increase with diversity and decrease with body size. Identifying and tackling the diversity of 'dark taxa' with scalable techniques emerge as urgent priorities in biodiversity science.

Molecular Systematics of the Firefly Genus Luciola (Coleoptera: Lampyridae: Luciolinae) with the Description of a New Species from Singapore.

The firefly genus Luciola sensu McDermott contains 282 species that are distributed across major parts of Asia, Europe, Africa, Australia, and the Pacific islands. Due to phenotypic similarities, species identification using external morphological characters can be unreliable for this group. Consequently, decades of piecemeal taxonomic treatments have resulted in numerous erroneous and contentious classifications. Furthermore, our understanding of the group's evolutionary history is limited due to the lack of a robust phylogenetic framework that has also impeded efforts to stabilize its taxonomy. Here, we constructed molecular phylogenies of Luciola and its allies based on combined mitogenomes and Cytochrome c oxidase subunit 1 (COX1) sequences including a newly sequenced mitogenome of an unidentified taxon from Singapore. Our results showed that this taxon represents a distinct and hitherto undescribed evolutionary lineage that forms a clade with L. filiformis from Japan and L. curtithorax from China. Additionally, the Singaporean lineage can be differentiated from other congeners through several external and internal diagnostic morphological characters, and is thus described herein as a new species. Our phylogeny also strongly supported the paraphyly of Luciola with regard to L. cruciata and L. owadai, which were inferred to be more closely related to the genus Aquatica as opposed to other members of Luciola sensu stricto. The genus Hotaria was inferred as a derived clade within Luciola (sister to L. italica), supporting its status as a subgenus of Luciola instead of a distinct genus. This is the first time since 1909 that a new species of luminous firefly has been discovered in Singapore, highlighting the need for continued biodiversity research, even in small, well-studied and highly developed countries, such as Singapore.

Description of the larva of a firefly species, Pygoluciola dunguna Nada (Coleoptera: Lampyridae).

Pygoluciola dunguna Nada, 2018 was described from Peninsular Malaysia, using males and reliably associated females. This paper details description of the larva which has been conclusively identified as Pygoluciola dunguna based on DNA barcoding technique and uses morphology, brief habitat and behavioural data. A total of 70 larval specimens were measured and their main features described. The larvae exhibit a riparian or semi-aquatic behaviour, observed crawling on the sandy edge of shallow streams. The stake-like projections along the length of the body suggest a form of defensive mechanism from falling prey to aquatic predators.

The firefly genus Pteroptyx Olivier revisited (Coleoptera: Lampyridae: Luciolinae).

The synchronous firefly genus Pteroptyx Olivier is reassessed from morphological, molecular, and habitat perspectives in Malaysia, and includes some reliably associated females described from morphological features and internal female reproductive anatomy. Phylogenetic analyses using combined morphological and molecular data (where available) for 158 taxa supported all the major features of the existing taxonomic categories within the Indopacific Luciolinae. They revealed a distinct Pteroptyx clade as a morphologically variable genus with Poluninius selangoriensis Ballantyne being newly synonymised with Luciola testacea Motschulsky, the type species, which is redescribed from the type series. Pteroptyx gelasina Ballantyne was shown to be distinct and three of the four morphological subdivisions within Pteroptyx malaccae (Gorham) considered useful. A new species Pt. balingiana Jusoh sp. nov. is described from Sarawak. A second specimen of Pt. gombakia Ballantyne is described and figured.        Some females were reliably associated with identified males by molecular data, but investigation of their morphology showed consistent features that were for the most part not useful for species delineation, which still relies on association with the males and colour patterns. All females investigated had bursa plates.Habitat details for most Pteroptyx revealed an association with a riparian environment likely to support mangroves but not necessarily an obligatory association with mangroves or any particular species. Pteroptyx galbina Jusoh was found up to 30 km from the sea, and Pt. bearni Olivier displays in a variety of flowering plants alongside rivers, including mangroves.Keys to species and diagnoses of all species with coloured plates are given.

Revisional studies on the Luciolinae fireflies of Asia (Coleoptera: Lampyridae): 1. The genus Pyrophanes Olivier with two new species. 2. Four new species of Pteroptyx Olivier and 3. A new genus Inflata Boontop, with redescription of Luciola indica (Motsch.) as Inflata indica comb. nov.

The Luciolinae firefly genus Pyrophanes is redescribed and a key is provided for 7 species, viz. appendiculata Olivier, beccarii Olivier, quadrimaculata Olivier, semilimbata (Olivier) and similis Olivier, with Py. elongata Ballantyne sp. nov. and Py. similisimma Ballantyne sp. nov. described as new. Macropterous females associated for several species have 2 pairs of broad bursa plates. Following an enlarged phylogenetic analysis of morphological characters, an expanded generic description of Pteroptyx Olivier now accommodates four new species with metafemoral combs. Three of these have an entire light organ in ventrite 7 but are without the generic hallmark of deflexed elytral apices in the male. The first species of Pteroptyx to possess these features are Pt. sayangia Ballantyne sp. nov., Pt. galbina Jusoh sp. nov. and Pt. surabayia Ballantyne sp. nov. Based on a single unusual specimen Pt. gombakia Ballantyne sp. nov. is here described with deflexed elytral apices and bipartite light organ in ventrite 7, but with exceptional incurving lobes along the posterior margin of ventrite 7, which is a characteristic of Pyrophanes. The description of Luciola testacea Motschulsky is discussed and many morphological characters of its type specimen are correctly outlined. Its place as the type for Pteroptyx is addressed. Inflata gen. nov. Boontop is erected for specimens of Luciola indica Motschulsky as Inflata indica (Motsch.) comb. nov., and is described from males and reliably associated females. Discussion overviews the present situation regarding Luciolinae taxonomy of southeast Asian and the Australopacific regions.