Revision of the Austrelatuspapuensis group with descriptions of 42 new species from New Guinea (Coleoptera, Dytiscidae, Copelatinae).

The Austrelatuspapuensis group is the second species group of the New Guinean representatives of the recently described genus AustrelatusShaverdo et al., 2023. The group is mainly defined by distinct scale- and/or spinula-like surface structures of the dorsal sclerite of the median lobe. The species group already contains four described species and 42 new species and one subspecies treated here: Austrelatusaiyurensissp. nov., A.asteiossp. nov., A.bewaniensissp. nov., A.bosaviensissp. nov., A.bundunensissp. nov., A.centralensissp. nov., A.craterensissp. nov., A.decorissp. nov., A.dekaisp. nov., A.epicharissp. nov., A.flavocapitatussp. nov., A.fuscussp. nov., A.herzogensissp. nov., A.inconstanssp. nov., A.iriatoisp. nov., A.kalibumisp. nov., A.kebarensissp. nov., A.kokodensissp. nov., A.leptossp. nov., A.lolokisp. nov., A.lopintolensissp. nov., A.madangensissp. nov., A.maindaisp. nov., A.mamberamosp. nov., A.mianminensissp. nov., A.miltokarenossp. nov., A.noiadisp. nov., A.normanbyensissp. nov., A.ohusp. nov., A.posmanisp. nov., A.procerussp. nov., A.pseudogestroisp. nov., A.pseudomianminensissp. nov., A.robustussp. nov., A.sarartisp. nov., A.sumokedisp. nov., A.wanangensissp. nov., A.wasiorensissp. nov., A.wasurensissp. nov., A.weigelisp. nov., A.yamurensissp. nov., A.yeretuarsp. nov., A.xanthocephalusnabirensisssp. nov. A checklist and identification key to New Guinean species of the group are provided and important diagnostic characters are illustrated. Data on the species distributions and habiat preferences are given.

Austrelatus gen. nov., a new genus of Australasian diving beetles (Coleoptera, Dytiscidae, Copelatinae), with the discovery of 31 new species from New Guinea.

Herein, Austrelatusgen. nov. (type species: Copelatusirregularis W.J. Macleay, 1871) is described for a distinctive lineage of predominantly Australasian species previously assigned to Copelatus Erichson, 1832. The new genus was retrieved as well supported, monophyletic clade in phylogenetic analysis of DNA sequences data using Bayesian and parsimony approaches. The main morphological diagnostic character of Austrelatus is a complex median lobe of the aedeagus, with evident dorsal and ventral sclerites usually divided in apical half into two lobes of different shape or otherwise modified. Morphological comparison of the new genus with other Copelatinae genera, especially with Copelatus and Exocelina Broun, 1886, and a generic key to the New Guinean Copelatinae are provided. New combinations are established for 31 already described species mainly from the Australian Region (all from Copelatus): Austrelatusadelbert (Megna, Atthakor, Manaono, Hendrich & Balke, 2017), comb. nov.; A.badeni (Sharp, 1882), comb. nov.; A.bakewelli (J. Balfour-Browne, 1939), comb. nov.; A.baranensis (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.bougainvillensis (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.boukali (Hendrich & Balke, 1998), comb. nov.; A.clarki (Sharp, 1882), comb. nov.; A.daemeli (Sharp, 1882), comb. nov.; A.davidi (Wewalka, 2017), comb. nov.; A.deccanensis (Sheth, Ghate & Hájek, 2018), comb. nov.; A.fidschiensis (Zimmermann, 1928), comb. nov.; A.gestroi (Régimbart, 1892), comb. nov.; A.irregularis (W.J. Macleay, 1871), comb. nov.; A.kaszabi (Guignot, 1956), comb. nov.; A.kietensis (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.laevipennis (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.luteomaculatus (Guignot, 1956), comb. nov.; A.maushomi (Sheth, Ghate & Hájek, 2018), comb. nov.; A.neoguineensis (Zimmermann, 1919), comb. nov.; A.nigrolineatus (Sharp, 1882), comb. nov.; A.papuensis (J. Balfour-Browne, 1939), comb. nov.; A.parallelus (Zimmermann, 1920a), comb. nov.; A.schuhi (Hendrich & Balke, 1998), comb. nov.; A.sibelaemontis (Hájek, Hendrich, Hawlitschek & Balke, 2010), comb. nov.; A.strigosulus (Fairmaire, 1878), comb. nov.; A.ternatensis (Régimbart, 1899), comb. nov.; A.uludanuensis (Hendrich & Balke, 1995), comb. nov.; A.urceolus (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.variistriatus (Hájek, Shaverdo, Hendrich & Balke, 2021), comb. nov.; A.wallacei (J. Balfour-Browne, 1939), comb. nov. and A.xanthocephalus (Régimbart, 1899), comb. nov.Austrelatus species from New Guinea are divided into two informal species groups, the A.neoguineensis group and A.papuensis group, and A.fumatosp. nov. and A.setiphallussp. nov. standing aside of them. The A.neoguineensis group is introduced with three previously known species and 29 new species described here based on the morphological characters and Cox1 data: Austrelatusbaliemsp. nov., A.bormensissp. nov., A.brazzasp. nov., A.debulensissp. nov., A.fakfaksp. nov., A.febrisaurisp. nov., A.fojaensissp. nov., A.garainensissp. nov., A.innominatussp. nov., A.lembenensissp. nov., A.lisaesp. nov., A.manokwariensissp. nov., A.mimikasp. nov., A.mirificussp. nov., A.moreguinensissp. nov., A.nadjaesp. nov., A.oksibilensissp. nov., A.pseudoneoguineensissp. nov., A.pseudoksibilensissp. nov., A.rajaampatensissp. nov., A.rouaffersp. nov., A.rugosussp. nov., A.sandaunensissp. nov., A.sarmiensissp. nov., A.securiformissp. nov., A.testegensissp. nov., A.toricellisp. nov., A.vagauensissp. nov., and A.wanggarensissp. nov.Copelatusvagestriatus Zimmermann, 1919, syn. nov. is recognised as a junior subjective synonym of A.clarki (Sharp, 1882). The lectotypes of Copelatusgestroi Régimbart, 1892, C.neoguineensis Zimmermann, 1919 and C.xanthocephalus Régimbart, 1899 are designated. All species are (re)described, and their important species characters (genitalia, habitus, and colour patterns) are illustrated. Keys to all species are provided. The known distribution and habitat preferences of each species are outlined briefly. New Guinean Austrelatus occupy a variety of stagnant water habitats, either lentic sensu stricto, or standing water associated with lotic habitats (e.g., backflows, rockpools, intermittent / ephemeral stream pools).

New Guinean orogenic dynamics and biota evolution revealed using a custom geospatial analysis pipeline.

BACKGROUND: The New Guinean archipelago has been shaped by millions of years of plate tectonic activity combined with long-term fluctuations in climate and sea level. These processes combined with New Guinea's location at the tectonic junction between the Australian and Pacific plates are inherently linked to the evolution of its rich endemic biota. With the advent of molecular phylogenetics and an increasing amount of geological data, the field of New Guinean biogeography begins to be reinvigorated. RESULTS: We inferred a comprehensive dated molecular phylogeny of endemic diving beetles to test historical hypotheses pertaining to the evolution of the New Guinean biota. We used geospatial analysis techniques to compare our phylogenetic results with a newly developed geological terrane map of New Guinea as well as the altitudinal and geographic range of species ( https://arcg.is/189zmz ). Our divergence time estimations indicate a crown age (early diversification) for New Guinea Exocelina beetles in the mid-Miocene ca. 17 Ma, when the New Guinean orogeny was at an early stage. Geographic and geological ancestral state reconstructions suggest an origin of Exocelina ancestors on the eastern part of the New Guinean central range on basement rocks (with a shared affinity with the Australian Plate). Our results do not support the hypothesis of ancestors migrating to the northern margin of the Australian Plate from Pacific terranes that incrementally accreted to New Guinea over time. However, our analyses support to some extent a scenario in which Exocelina ancestors would have been able to colonize back and forth between the amalgamated Australian and Pacific terranes from the Miocene onwards. Our reconstructions also do not support an origin on ultramafic or ophiolite rocks that have been colonized much later in the evolution of the radiation. Macroevolutionary analyses do not support the hypothesis of heterogeneous diversification rates throughout the evolution of this radiation, suggesting instead a continuous slowdown in speciation. CONCLUSIONS: Overall, our geospatial analysis approach to investigate the links between the location and evolution of New Guinea's biota with the underlying geology sheds a new light on the patterns and processes of lineage diversification in this exceedingly diverse region of the planet.

Trade-offs between multifunctionality and profit in tropical smallholder landscapes.

Land-use transitions can enhance the livelihoods of smallholder farmers but potential economic-ecological trade-offs remain poorly understood. Here, we present an interdisciplinary study of the environmental, social and economic consequences of land-use transitions in a tropical smallholder landscape on Sumatra, Indonesia. We find widespread biodiversity-profit trade-offs resulting from land-use transitions from forest and agroforestry systems to rubber and oil palm monocultures, for 26,894 aboveground and belowground species and whole-ecosystem multidiversity. Despite variation between ecosystem functions, profit gains come at the expense of ecosystem multifunctionality, indicating far-reaching ecosystem deterioration. We identify landscape compositions that can mitigate trade-offs under optimal land-use allocation but also show that intensive monocultures always lead to higher profits. These findings suggest that, to reduce losses in biodiversity and ecosystem functioning, changes in economic incentive structures through well-designed policies are urgently needed.

Phylogeography and population genomics of a lotic water beetle across a complex tropical landscape.

The habitat template concept applied to a freshwater system indicates that lotic species, or those which occupy permanent habitats along stream courses, are less dispersive than lentic species, or those that occur in more ephemeral aquatic habitats. Thus, populations of lotic species will be more structured than those of lentic species. Stream courses include both flowing water and small, stagnant microhabitats that can provide refuge when streams are low. Many species occur in these microhabitats but remain poorly studied. Here, we present population genetic data for one such species, the tropical diving beetle Exocelina manokwariensis (Dytiscidae), sampled from six localities along a ~300 km transect across the Birds Head Peninsula of New Guinea. Molecular data from both mitochondrial (CO1 sequences) and nuclear (ddRAD loci) regions document fine-scale population structure across populations that are ~45 km apart. Our results are concordant with previous phylogenetic and macroecological studies that applied the habitat template concept to aquatic systems. This study also illustrates that these diverse but mostly overlooked microhabitats are promising study systems in freshwater ecology and evolutionary biology. With the advent of next-generation sequencing, fine-scale population genomic studies are feasible for small nonmodel organisms to help illuminate the effect of habitat stability on species' natural history, population structure and geographic distribution.

Stream flow alone does not predict population structure of diving beetles across complex tropical landscapes.

Recent theoretical advances have hypothesized a central role of habitat persistence on population genetic structure and resulting biodiversity patterns of freshwater organisms. Here, we address the hypothesis that lotic species, or lineages adapted to comparably geologically stable running water habitats (streams and their marginal habitats), have high levels of endemicity and phylogeographic structure due to the persistent nature of their habitat. We use a nextRAD DNA sequencing approach to investigate the population structure and phylogeography of a putatively widespread New Guinean species of diving beetle, Philaccolilus ameliae (Dytiscidae). We find that P. ameliae is a complex of morphologically cryptic, but geographically and genetically well-differentiated clades. The pattern of population connectivity is consistent with theoretical predictions associated with stable lotic habitats. However, in two clades, we find a more complex pattern of low population differentiation, revealing dispersal across rugged mountains and watersheds of New Guinea up to 430 km apart. These results, while surprising, were also consistent with the original formulation of the habitat template concept by Southwood, involving lineage-idiosyncratic evolution in response to abiotic factors. In our system, low population differentiation might reflect a young species in a phase of range expansion utilizing vast available habitat. We suggest that predictions of life history variation resulting from the dichotomy between lotic and lentic organisms require more attention to habitat characterization and microhabitat choice. Our results also underpin the necessity to study fine-scale processes but at a larger geographical scale, as compared to solely documenting macroecological patterns, to understand ecological drivers of regional biodiversity. Comprehensive sampling especially of tropical lineages in complex and threatened environments such as New Guinea remains a critical challenge.

A new, widely distributed species of the Exocelina ekari-group from West Papua (Coleoptera, Dytiscidae, Copelatinae).

Exocelina manokwariensis sp. n. from West Papua is placed into the Exocelina ekari-group based on the structure of its male genitalia. The new species is described, including its three subspecies, from the mainland of West Papua, Waigeo Island, Batanta and Salawati Islands, and Bomberai peninsula. An identification key to the subspecies as well as data on species distribution are provided.

Description of 23 new species of the Exocelinaekari-group from New Guinea, with a key to all representatives of the species group (Coleoptera, Dytiscidae, Copelatinae).

Twenty three new species of Exocelina Broun, 1886 from New Guinea are described herein: Exocelinabewaniensis sp. n., Exocelinabismarckensis sp. n., Exocelinacraterensis sp. n., Exocelinagorokaensis sp. n., Exocelinaherowana sp. n., Exocelinajimiensis sp. n., Exocelinakisli sp. n., Exocelinaksionseki sp. n., Exocelinalembena sp. n., Exocelinamantembu sp. n., Exocelinamichaelensis sp. n., Exocelinapinocchio sp. n., Exocelinapseudoastrophallus sp. n., Exocelinapseudobifida sp. n., Exocelinapseudoedeltraudae sp. n., Exocelinapseudoeme sp. n., Exocelinasandaunensis sp. n., Exocelinasimbaiarea sp. n., Exocelinaskalei sp. n., Exocelinatabubilensis sp. n., Exocelinatariensis sp. n., Exocelinavovai sp. n., and Exocelinawannangensis sp. n. All of them have been found to belong to the Exocelinaekari-group. An identification key to all known species of the group is provided, and important diagnostic characters (habitus, color, male antennae, protarsomeres 4-5, median lobes, and parameres) are illustrated. Data on the distribution of the new species and some already described species are given.