Image-Based Automated Species Identification: Can Virtual Data Augmentation Overcome Problems of Insufficient Sampling?

Automated species identification and delimitation is challenging, particularly in rare and thus often scarcely sampled species, which do not allow sufficient discrimination of infraspecific versus interspecific variation. Typical problems arising from either low or exaggerated interspecific morphological differentiation are best met by automated methods of machine learning that learn efficient and effective species identification from training samples. However, limited infraspecific sampling remains a key challenge also in machine learning. In this study, we assessed whether a data augmentation approach may help to overcome the problem of scarce training data in automated visual species identification. The stepwise augmentation of data comprised image rotation as well as visual and virtual augmentation. The visual data augmentation applies classic approaches of data augmentation and generation of artificial images using a generative adversarial networks approach. Descriptive feature vectors are derived from bottleneck features of a VGG-16 convolutional neural network that are then stepwise reduced in dimensionality using Global Average Pooling and principal component analysis to prevent overfitting. Finally, data augmentation employs synthetic additional sampling in feature space by an oversampling algorithm in vector space. Applied on four different image data sets, which include scarab beetle genitalia (Pleophylla, Schizonycha) as well as wing patterns of bees (Osmia) and cattleheart butterflies (Parides), our augmentation approach outperformed a deep learning baseline approach by means of resulting identification accuracy with nonaugmented data as well as a traditional 2D morphometric approach (Procrustes analysis of scarab beetle genitalia). [Deep learning; image-based species identification; generative adversarial networks; limited infraspecific sampling; synthetic oversampling.].

The evolution and genomic basis of beetle diversity.

The order Coleoptera (beetles) is arguably the most speciose group of animals, but the evolutionary history of beetles, including the impacts of plant feeding (herbivory) on beetle diversification, remain poorly understood. We inferred the phylogeny of beetles using 4,818 genes for 146 species, estimated timing and rates of beetle diversification using 89 genes for 521 species representing all major lineages and traced the evolution of beetle genes enabling symbiont-independent digestion of lignocellulose using 154 genomes or transcriptomes. Phylogenomic analyses of these uniquely comprehensive datasets resolved previously controversial beetle relationships, dated the origin of Coleoptera to the Carboniferous, and supported the codiversification of beetles and angiosperms. Moreover, plant cell wall-degrading enzymes (PCWDEs) obtained from bacteria and fungi via horizontal gene transfers may have been key to the Mesozoic diversification of herbivorous beetles-remarkably, both major independent origins of specialized herbivory in beetles coincide with the first appearances of an arsenal of PCWDEs encoded in their genomes. Furthermore, corresponding (Jurassic) diversification rate increases suggest that these novel genes triggered adaptive radiations that resulted in nearly half of all living beetle species. We propose that PCWDEs enabled efficient digestion of plant tissues, including lignocellulose in cell walls, facilitating the evolution of uniquely specialized plant-feeding habits, such as leaf mining and stem and wood boring. Beetle diversity thus appears to have resulted from multiple factors, including low extinction rates over a long evolutionary history, codiversification with angiosperms, and adaptive radiations of specialized herbivorous beetles following convergent horizontal transfers of microbial genes encoding PCWDEs.

Sex-Biased Dispersal Obscures Species Boundaries in Integrative Species Delimitation Approaches.

Accurate delimitation of species is crucial for a stable taxonomy, which provides the foundation for the study of evolutionary biology, ecology, and essentially all biological disciplines. Several approaches toward impartial and repeatable taxonomic practices are available but all existing methods have potentially unacceptable shortcomings. In particular, problems can arise when the underlying model assumptions are violated, for instance, in the presence of reduced gene flow. This is observed in the context of sex-biased dispersal, which is a common but underappreciated feature in many groups of organisms. Previously, simulations have indicated that sex-biased dispersal may lead to erroneous estimations of the true species numbers. However, this phenomenon has never been examined using empirical data. We evaluate the bias introduced by extreme female philopatry on a range of de novo [GMYC, PTP, ABGD, statistical parsimony, trinomial distribution of triplets model (tr2)] and validation (STACEY, iBPP) approaches to species delimitation in the scarab beetle genus Pachypus. Since female philopatry exhibited in this genus in particular can affect mitochondrial gene flow, we compared the results from analyses of single loci, mitochondrial loci, nuclear loci and combined data, as well as the performance of morphometric data as a secondary data source in a fully integrative Bayesian framework. Large overestimation of species numbers was observed across all analyses of combined and mitochondrial DNA data sets, suggesting specimens from nearly every sampling location as separate species. The use of nuclear data resulted in more reasonable estimations of species boundaries, which were largely supported by morphometrics of linear measurements, while geometric morphometrics of body outlines resulted in stronger splitting. Simulations of population divergence with migration, corresponding to the biology of Pachypus, showed that female philopatry strongly increases reciprocal monophyly of mitochondrial markers and may substantially contribute to over-splitting in species delimitation. Robust results recovered using nuclear DNA and morphological data nevertheless enabled us to reach novel conclusions about species boundaries in Pachypus. Our findings suggest that mitochondrial DNA will be less suited to species delimitation in many cases, in particular in the presence of sex-biased dispersal.

Small-scale topography modulates elevational α-, ß- and γ-diversity of Andean leaf beetles.

Elevational diversity gradients are typically studied without considering the complex small-scale topography of large mountains, which generates habitats of strongly different environmental conditions within the same elevational zones. Here we analyzed the importance of small-scale topography for elevational diversity patterns of hyperdiverse tropical leaf beetles (Coleoptera: Chrysomelidae). We compared patterns of elevational diversity and species composition of beetles in two types of forests (on mountain ridges and in valleys) and analyzed whether differences in the rate of species turnover among forest habitats lead to shifts in patterns of elevational diversity when scaling up from the local study site to the elevational belt level. We sampled beetle assemblages at 36 sites in the Podocarpus National Park, Ecuador, which were equally distributed over two forest habitats and three elevational levels. DNA barcoding and Poisson tree processes modelling were used to delimitate putative species. On average, local leaf beetle diversity showed a clear hump-shaped pattern. However, only diversity in forests on mountain ridges peaked at mid-elevation, while beetle diversity in valleys was similarly high at low- and mid-elevation and only declined at highest elevations. A higher turnover of species assemblages at lower than at mid-elevations caused a shift from a hump-shaped diversity pattern found at the local level to a low-elevation plateau pattern (with similar species numbers at low and mid-elevation) at the elevational belt level. Our study reveals an important role of small-scale topography and spatial scale for the inference on gradients of elevational species diversity.

Landscape genetics indicate recently increased habitat fragmentation in African forest-associated chafers.

Today, indigenous forests cover less than 0.6% of South Africa's land surface and are highly fragmented. Most forest relicts are very small and typically occur in fire-protected gorges along the eastern Great Escarpment. Yet, they hold a unique and valuable fauna with high endemism and ancient phylogenetic lineages, fostered by long-term climatic stability and complex microclimates. Despite numerous studies on southern African vegetation cover, the current state of knowledge about the natural extension of indigenous forests is rather fragmentary. We use an integrated approach of population-level phylogeography and climatic niche modeling of forest-associated chafer species to assess connectivity and extent of forest habitats since the last glacial maximum. Current and past species distribution models ascertained potential fluctuations of forest distribution and supported a much wider potential current extension of forests based on climatic data. Considerable genetic admixture of mitochondrial and nuclear DNA among many populations and an increase in mean population mutation rate in Extended Bayesian Skyline Plots of all species indicated more extended or better connected forests in the recent past (<5 kya). Genetic isolation of certain populations, as revealed by population differentiation statistics (GST'), as well as landscape connectivity statistics and habitat succession scenarios suggests considerable loss of habitat connectivity. As major anthropogenic influence is likely, conservational actions need to be considered.

Rarity and Incomplete Sampling in DNA-Based Species Delimitation.

DNA-based species delimitation may be compromised by limited sampling effort and species rarity, including "singleton" representatives of species, which hampers estimates of intra- versus interspecies evolutionary processes. In a case study of southern African chafers (beetles in the family Scarabaeidae), many species and subclades were poorly represented and 48.5% of species were singletons. Using cox1 sequences from >500 specimens and ∼100 species, the Generalized Mixed Yule Coalescent (GMYC) analysis as well as various other approaches for DNA-based species delimitation (Automatic Barcode Gap Discovery (ABGD), Poisson tree processes (PTP), Species Identifier, Statistical Parsimony), frequently produced poor results if analyzing a narrow target group only, but the performance improved when several subclades were combined. Hence, low sampling may be compensated for by "clade addition" of lineages outside of the focal group. Similar findings were obtained in reanalysis of published data sets of taxonomically poorly known species assemblages of insects from Madagascar. The low performance of undersampled trees is not due to high proportions of singletons per se, as shown in simulations (with 13%, 40% and 52% singletons). However, the GMYC method was highly sensitive to variable effective population size ([Formula: see text]), which was exacerbated by variable species abundances in the simulations. Hence, low sampling success and rarity of species affect the power of the GMYC method only if they reflect great differences in [Formula: see text] among species. Potential negative effects of skewed species abundances and prevalence of singletons are ultimately an issue about the variation in [Formula: see text] and the degree to which this is correlated with the census population size and sampling success. Clade addition beyond a limited study group can overcome poor sampling for the GMYC method in particular under variable [Formula: see text] This effect was less pronounced for methods of species delimitation not based on coalescent models.

A historical biogeography of megadiverse Sericini-another story "out of Africa"?

Megadiverse insect groups present special difficulties for biogeographers because poor classification, incomplete knowledge of taxonomy, and many undescribed species can introduce a priori sampling bias to any analysis. The historical biogeography of Sericini, a tribe of melolonthine scarabs comprising about 4000 species, was investigated using the most comprehensive and time-calibrated molecular phylogeny available today. Problems arising through nomenclatural confusion were overcome by extensive sampling (665 species) from all major lineages of the tribe. A West Gondwanan origin of Sericini (c. 112 Ma) was reconstructed using maximum parsimony, maximum-likelihood and model-based ancestral area estimation. Vicariance in the tribe's earliest history separated Neotropical and Old World Sericini, whereas subsequent lower Cretaceous biogeography of the tribe was characterized by repeated migrations out of Africa, resulting in the colonization of Eurasia and Madagascar. North America was colonized from Asia during the Cenozoic and a lineage of "Modern Sericini" reinvaded Africa. Diversification dynamics revealed three independent shifts to increased speciation rates: in African ant-adapted Trochalus, Oriental Tetraserica, and Asian and African Sericina. Southern Africa is proposed as both cradle and refuge of Sericini. This area has retained many old lineages that portray the evolution of the African Sericini fauna as a series of taxon pulses.

Bayesian species delimitation in Pleophylla chafers (Coleoptera) - the importance of prior choice and morphology.

BACKGROUND: Defining species units can be challenging, especially during the earliest stages of speciation, when phylogenetic inference and delimitation methods may be compromised by incomplete lineage sorting (ILS) or secondary gene flow. Integrative approaches to taxonomy, which combine molecular and morphological evidence, have the potential to be valuable in such cases. In this study we investigated the South African scarab beetle genus Pleophylla using data collected from 110 individuals of eight putative morphospecies. The dataset included four molecular markers (cox1, 16S, rrnL, ITS1) and morphometric data based on male genital morphology. We applied a suite of molecular and morphological approaches to species delimitation, and implemented a novel Bayesian approach in the software iBPP, which enables continuous morphological trait and molecular data to be combined. RESULTS: Traditional morphology-based species assignments were supported quantitatively by morphometric analyses of the male genitalia (eigenshape analysis, CVA, LDA). While the ITS1-based delineation was also broadly congruent with the morphospecies, the cox1 data resulted in over-splitting (GMYC modelling, haplotype networks, PTP, ABGD). In the most extreme case morphospecies shared identical haplotypes, which may be attributable to ILS based on statistical tests performed using the software JML. We found the strongest support for putative morphospecies based on phylogenetic evidence using the combined approach implemented in iBPP. However, support for putative species was sensitive to the use of alternative guide trees and alternative combinations of priors on the population size (θ) and rootage (τ 0 ) parameters, especially when the analysis was based on molecular or morphological data alone. CONCLUSIONS: We demonstrate that continuous morphological trait data can be extremely valuable in assessing competing hypotheses to species delimitation. In particular, we show that the inclusion of morphological data in an integrative Bayesian framework can improve the resolution of inferred species units. However, we also demonstrate that this approach is extremely sensitive to guide tree and prior parameter choice. These parameters should be chosen with caution - if possible - based on independent empirical evidence, or careful sensitivity analyses should be performed to assess the robustness of results. Young species provide exemplars for investigating the mechanisms of speciation and for assessing the performance of tools used to delimit species on the basis of molecular and/or morphological evidence.

A molecular phylogeny of rose chafers (Coleoptera: Scarabaeidae: Cetoniinae) reveals a complex and concerted morphological evolution related to their flight mode.

Rose chafers (Cetoniinae) are a large group of flower visitors within the pleurostict Scarabaeidae that are characterized by their distinctive flight mode with nearly closed forewings. Despite their popularity, this is the first study to use molecular data to infer their phylogenetic relationships. We used partial gene sequences for 28S rRNA, cytochrome oxidase I (cox1) and 16S rRNA (rrnL) for 299 species, representing most recognized subfamilies of Scarabaeidae, including 125 species of Cetoniinae. Combined analyses using maximum parsimony, maximum likelihood and Bayesian inferences recovered Cetoniinae as monophyletic in all analyses, with the sister clade composed of Rutelinae and Dynastinae. Rutelinae was always recovered as paraphyletic with respect to Dynastinae. Trichiini sensu lato (s.l.) was recovered as a polyphyletic clade, while Cetoniini s.l. was recovered as paraphyletic. The inferred topologies were also supported by site bootstrapping of the ML trees. With the exception of Cremastochelini, most tribes of Cetoniinae were poly- or paraphyletic, indicating the critical need for a careful revision of rose chafer classification. Analysis of elytral base structure (including 11 scored characters) in the context of phylogeny, revealed a complex, concerted and rapid transformation of the single trait elements linked to a modified flight mode with closed elytra. This appears to be unlinked to the lateral sinuation of the elytra, which originated independently several times at later stages in the evolution of the group.

The evolution of scarab beetles tracks the sequential rise of angiosperms and mammals.

Extant terrestrial biodiversity arguably is driven by the evolutionary success of angiosperm plants, but the evolutionary mechanisms and timescales of angiosperm-dependent radiations remain poorly understood. The Scarabaeoidea is a diverse lineage of predominantly plant- and dung-feeding beetles. Here, we present a phylogenetic analysis of Scarabaeoidea based on four DNA markers for a taxonomically comprehensive set of specimens and link it to recently described fossil evidence. The phylogeny strongly supports multiple origins of coprophagy, phytophagy and anthophagy. The ingroup-based fossil calibration of the tree widely confirmed a Jurassic origin of the Scarabaeoidea crown group. The crown groups of phytophagous lineages began to radiate first (Pleurostict scarabs: 108 Ma; Glaphyridae between 101 Ma), followed by the later diversification of coprophagous lineages (crown-group age Scarabaeinae: 76 Ma; Aphodiinae: 50 Ma). Pollen feeding arose even later, at maximally 62 Ma in the oldest anthophagous lineage. The clear time lag between the origins of herbivores and coprophages suggests an evolutionary path driven by the angiosperms that first favoured the herbivore fauna (mammals and insects) followed by the secondary radiation of the dung feeders. This finding makes it less likely that extant dung beetle lineages initially fed on dinosaur excrements, as often hypothesized.

Species Diagnosis and DNA Taxonomy.

The use of DNA has helped to improve and speed up species identification and delimitation. However, it also provides new challenges to taxonomists. Incongruence of outcome from various markers and delimitation methods, bias from sampling and skewed species distribution, implemented models, and the choice of methods/priors may mislead results and also may, in conclusion, increase elements of subjectivity in species taxonomy. The lack of direct diagnostic outcome from most contemporary molecular delimitation approaches and the need for a reference to existing and best sampled trait reference systems reveal the need for refining the criteria of species diagnosis and diagnosability in the current framework of nomenclature codes and good practices to avoid nomenclatorial instability, parallel taxonomies, and consequently more and new taxonomic impediment.

On the publication year of Sericini genera and species described by Brenske in Die Serica-Arten der Erde (Coleoptera: Scarabaeidae: Sericinae).

The year of publication of Brenskes species and genera described in his opus Die Serica-Arten der Erde is updated following up an overlooked delay of some of the fascicules of the Berliner Entomologische Zeitschrift, namely the volumes 42, 43, and 46. This change affects 201 species group names and 20 genus group names, many of which have been revised in the past three decades, but no change of priority of other names occurred. The spelling of Mericserica oberthueri Brenske, 1899 is corrected.

The genus Dedalopterus Sabatinelli & Pontuale, 1998 (Scarabaeidae: Melolonthinae: Leucopholini) in Laos and Vietnam, with description of a new species.

The genus Dedalopterus Sabatinelli & Pontuale, 1998 from Laos and Vietnam is reviewed: three species are present of which Dedalopterus lexuanhuei Pham, Ahrens & Sabatinelli, new species from Central Vietnam (Ngoc Linh Mts., Annamite Range) is here described. Dedalopterusmalyszi Bunalski, 2001 is present in North Vietnam (Lao Cai, Hoang Lien Son Range), and Dedalopterus pulchellus Sabatinelli & Pontuale, 1998 (= D.bezdekorum Zdek & Krajk, 2007, new synonymy) is known from Northeast Laos (Mt. Xiangkhouang and Mt. Phou Pan). Additional records, an updated checklist, and an identification key of the genus Dedalopterus are provided. All species treated are abundantly illustrated.

Metazoa-level USCOs as markers in species delimitation and classification.

Metazoa-level universal single-copy orthologs (mzl-USCOs) are universally applicable markers for DNA taxonomy in animals that can replace or supplement single-gene barcodes. Previously, mzl-USCOs from target enrichment data were shown to reliably distinguish species. Here, we tested whether USCOs are an evenly distributed, representative sample of a given metazoan genome and therefore able to cope with past hybridization events and incomplete lineage sorting. This is relevant for coalescent-based species delimitation approaches, which critically depend on the assumption that the investigated loci do not exhibit autocorrelation due to physical linkage. Based on 239 chromosome-level assembled genomes, we confirmed that mzl-USCOs are genetically unlinked for practical purposes and a representative sample of a genome in terms of reciprocal distances between USCOs on a chromosome and of distribution across chromosomes. We tested the suitability of mzl-USCOs extracted from genomes for species delimitation and phylogeny in four case studies: Anopheles mosquitos, Drosophila fruit flies, Heliconius butterflies and Darwin's finches. In almost all instances, USCOs allowed delineating species and yielded phylogenies that corresponded to those generated from whole genome data. Our phylogenetic analyses demonstrate that USCOs may complement single-gene DNA barcodes and provide more accurate taxonomic inferences. Combining USCOs from sources that used different versions of ortholog reference libraries to infer marker orthology may be challenging and, at times, impact taxonomic conclusions. However, we expect this problem to become less severe as the rapidly growing number of reference genomes provides a better representation of the number and diversity of organismal lineages.

Integrative analysis of DNA phylogeography and morphology of the European rose chafer (Cetonia aurata) to infer species taxonomy and patterns of postglacial colonisation in Europe.

Integrative taxonomy has been proposed as a framework to unify new conceptual and methodological developments in quantitative assessment of trait variation used in species delimitation, but empirical studies in this young branch of systematics are rare. Here we use standard phylogenetic and parsimony network analyses on nuclear and mitochondrial DNA (Cox1, ITS1) of 230 individuals from 65 European sampling sites in order to deduce population structure of Cetonia beetles from geno- and haplotypes. Statistical measures of population differentiation are inferred on genealogical and geographical scales to test hypotheses about species limits and population history. By combining results of phylogenetic structure with features of morphology, including genital shape morphometrics and discrete external body characters, as well as with measures of population genetics, we attempt to integrate the results as a test of the validity of species limits, in particular of currently recognised subspecies. Despite high Cox1 divergence between some haplotype lineages, even some sympatric lineages (9%, e.g. N2 vs. N4), nDNA and morphology, as well as pattern of geographical and genealogical divergence measured by AMOVA analysis did not support the hypothesis of separate species. Highest divergence in nuclear markers was found among Italian populations of C. aurata pisana and C. a. sicula, and moderately high fixation indices along measurable morphological divergence suggest the correctness of their status as 'subspecies'. Divergence time estimates of the lineages suggest a glacial divergence in different refugia between the major haplogroups, while population differentiation in mtDNA among these was primarily attributable to restricted gene flow caused by geographic isolation.

Updates on the taxonomy and distribution of Gastroserica Brenske, 1897, Microserica Brenske, 1894, and Moronoserica Ahrens, Lukic & Liu, 2023 (Coleoptera: Scarabaeidae: Sericinae: Sericini).

A short update on the taxonomy of Gastroserica Brenske, 1897 is given. Two new species of the subgenus Helioserica Ahrens, Lukic & Liu, 2023, and one new species of the nominotypical subgenus are described: Gastroserica (H.) kachin Ahrens & Pham, new species (from Myanmar), G. (H.) horii Ahrens & Pham, new species, and G. (G.) muongphangensis Ahrens & Pham, new species (both from Vietnam). One name is synonymized: Gastroserica (G.) wenzhui Liu & Ahrens, 2014 (= Gastroserica skalei Ahrens & Fabrizi, 2018, new synonymy). Additional new records of the recently revised Microserica Brenske, 1894, and Moronoserica Ahrens, Lukic & Liu, 2023 as well as of Gastroserica are given. The diagnostic characters of the new taxa are illustrated. A corrective note for Ahrens et al. (2023) is also given, regarding the omitted but previously published synonymy of Microserica pusilla (Thunberg, 1818) (= Microserica compressipes (Weidemann, 1823)).

New species of the tribe Sericini Kirby, 1837 from China, with further updates on their taxonomy and distribution (Coleoptera: Scarabaeidae: Sericinae).

Fifteen new species of Sericini are described from China, including Gastroserica (s. str.) mayunshui Zhao & Ahrens, new species, Pachyserica albopunctata Zhao & Ahrens, new species, P. dongnanensis Zhao & Ahrens, new species, P. jianfengensis Zhao & Ahrens, new species, Serica (s. l.) caiyiyiae Zhao & Ahrens, new species, S. (s. l.) babaoshanensis Zhao & Ahrens, new species, S. (s. l.) jicaiyanae Zhao & Ahrens, new species, S. (s. l.) zhangyaonani Zhao & Ahrens, new species, S. (s. l.) longidentata Zhao & Ahrens, new species, S. (s. l.) callosericoides Zhao & Ahrens, new species, S. (Taiwanoserica) liboyani Zhao & Ahrens, new species, S. (T.) yangzaichuni Zhao & Ahrens, new species, Maladera zhanchaoi Zhao & Ahrens, new species M. parabikouensis Zhao & Ahrens, new species and M. shikengkongensis Zhao & Ahrens, new species. Maladera juxianensis Ahrens, Fabrizi & Liu, 2021 was recognized as a junior synonym of M. aureola (Murayama, 1938). Additional collecting data for 32 other sericine species is presented.

A taxonomic review of Microserica Brenske, 1894 from continental Asia (Coleoptera: Scarabaeidae: Melolonthinae: Sericini).

The current paper gives an overview of the species of continental Asia so far assigned to the genus Microserica Brenske, 1894. Moronoserica Ahrens, Lukic & Liu, new genus, and Gastroserica (Helioserica Ahrens, Lukic & Liu, new subgenus), and 33 new species are described: Gastroserica bannok Ahrens, Lukic & Liu, new species, G. fumaria Ahrens, Lukic & Liu, new species, G. ivoi Ahrens, Lukic & Liu, new species, G. loei Ahrens, Lukic & Liu, new species, G. lucidomarginalis Ahrens, Lukic & Liu, new species, G. phukradung Ahrens, Lukic & Liu, new species, G. piceocoerulea Ahrens, Lukic & Liu, new species, G. rubropicea Ahrens, Lukic & Liu, new species, G. simaoensis Ahrens, Lukic & Liu, new species, G. yuebaensis Ahrens, Lukic & Liu, new species, Microserica allovarians Ahrens, Lukic & Liu, new species, Mic. banlaoana Ahrens, Lukic & Liu, new species, Mic. caiyangheana Ahrens, Lukic & Liu, new species, Mic. chaiyaphum Ahrens, Lukic & Liu, new species, Mic. cucphuong Ahrens, Lukic & Liu, new species, Mic. ferestictica Ahrens, Lukic & Liu, new species, Mic. hieroglyphica Ahrens, Lukic & Liu, new species, Mic. multipunctata Ahrens, Lukic & Liu, new species, Mic. namnao Ahrens, Lukic & Liu, new species, Mic. neosimplex Ahrens, Lukic & Liu, new species, Mic. parasimplex Ahrens, Lukic & Liu, new species, Mic. paravicula Ahrens, Lukic & Liu, new species, Mic. planiforceps Ahrens, Lukic & Liu, new species, Mic. viengvai Ahrens, Lukic & Liu, new species, Mic. vinden Ahrens, Lukic & Liu, new species, Mic. vipinglangensis Ahrens, Lukic & Liu, new species, Moronoserica banmethout Ahrens, Lukic & Liu, new species, Mor. renong Ahrens, Lukic & Liu, new species, Mor. squamulatoides Ahrens, Lukic & Liu, new species, Mor. songbae Ahrens, Lukic & Liu, new species, Mor. thungyai Ahrens, Lukic & Liu, new species, Oxyserica bifascipennis Ahrens, Lukic & Liu, new species, O. serena Ahrens, Lukic & Liu, new species. The revision results in 39 new combinations: Gastroserica bisignata (Nomura, 1974) new combination, G. cognata (Frey, 1972) new combination, G. dohertyi (Ahrens & Fabrizi, 2009) new combination, G. hiulca (Brenske, 1897) new combination, G. lucens (Ahrens & Fabrizi, 2009) new combination, G. nitidipyga (Nomura, 1974) new combination, G. quateorum (Frey, 1972) new combination, G. roingensis (Fabrizi & Ahrens, 2016) new combination, G. varians (Moser, 1915) new combination, Microserica avicula (Arrow, 1946) new combination, Mic. costisquamosa (Ahrens, Fabrizi & Liu, 2019) new combination, Mic. septemfoliata (Frey, 1972) new combination, Moronoserica banvaneue (Bohacz & Ahrens, 2020) new combination, Mor. crenatostriata (Ahrens, 2004) new combination, Mor. geberbauer (Ahrens, 2004) new combination, Mor. ginae (Bohacz & Ahrens, 2020) new combination, Mor. helferi (Bohacz & Ahrens, 2020) new combination, Mor. lineata (Moser, 1915) new combination, Mor. squamulata (Moser, 1915) new combination, Mor. tenasserimensis (Bohacz & Ahrens, 2020) new combination, Mor. ventrosa (Bohacz & Ahrens, 2020) new combination, Oxyserica arunensis (Ahrens, 1998) new combination, O. bhutanensis (Frey, 1975) new combination, O. cechovskyi (Ahrens, 1999) new combination, O. diversicornis (Moser, 1915) new combination, O. elegans (Frey, 1975) new combination, O. gandakiensis (Ahrens, 1998) new combination, O. hispidula (Frey, 1975) new combination, O. interrogator (Arrow, 1946) new combination, O. marginata (Brenske, 1896) new combination, O. martensi (Ahrens, 1998) new combination, O. myagdiana (Ahrens, 1998) new combination, O. nigropicta (Fairmaire, 1891) new combination, O. pedongensis (Ahrens, 1998) new combination, O. pruinosa (Hope, 1831) new combination, O. schawalleri (Ahrens, 1998) new combination, O. schulzei (Ahrens, 1998) new combination, O. steelei (Ahrens, 2004) new combination, O. truncata (Brenske, 1898) new combination. Lectotypes were designated of Microserica hiulca Brenske, 1897 and Serica nigropicta Fairmaire, 1891. A checklist and key to genera, species groups, and species is given, the diagnostic characters of the newly revised taxa and their distribution is illustrated.

A new species and new records of Sericini chafers from the Lower Gangetic Plains in India (Coleoptera: Scarabaeidae: Sericinae).

Here, we investigated the diversity of Sericini in the faunistically rather unknown Lower Gangetic plains in North India, based on material from the collection of the Zoological Survey of India. We discovered one new species from West Bengal, Maladerakolkataensis Bhunia, Gupta, Sarkar & Ahrens, and provide further records of an additional 23 species belonging to five genera from the lowlands of the states Bihar and West Bengal. Out of these, 21 species represent new state records: 12 for Bihar and nine for West Bengal. All recorded species are briefly documented by diagnostic illustrations.

Local stochastics and ecoclimatic situation shape phytophagous chafer assemblage composition.

Very little is known about factors determining the assemblage structure of megadiverse polyphagous-herbivore scarab chafers in the tropics (Coleoptera: Scarabaeidae). Here, we examined the composition of Sri Lankan chafer assemblages and investigated whether it is influenced more by the general ecoclimatic situation, macrohabitat, or indetermined stochastic biotic and abiotic factors of each locality. We also explored the influence of the latter on separate lineages and general body size. Based on dedicated field surveys conducted during the dry and wet seasons, we examined 4847 chafer individuals of 105 species sampled using multiple UV-light traps in 11 localities covering different forest types and altitudinal zones. Assemblages were assessed for compositional similarity, species diversity, and abundance within four major eco-spatial partitions: forest types, elevational zones, localities, and macrohabitats. Our results revealed that assemblages were shaped mainly by locality stochastics (i.e., multi-factor ensemble of all biotic and abiotic environmental conditions at local scale), and to a minor extent by ecoclimatic conditions. Macrohabitat had little effect on the assemblage composition. This was true for the entire chafer assemblage as well as for all single lineages or different body size classes. However, in medium and large species the contrasts between localities were less pronounced, which was not the case for individual lineages of the assemblage. Contrasts of assemblage similarity between localities were much more evident than those for forest types and elevation zones. Significant correlation between species composition and geographic distance was found only for the assemblage of small-bodied specimens. Seasonal change (dry-wet) in species composition was minor and only measurable in a few localities. The strong turnover between examined localities corroborates with the high degree of endemism in many phytophagous chafers, particularly in Sericini. Connected with their hypothetic poor habitat specificity and polyphagy, this might also explain why so many chafer crop pests in the Asian tropics are endemics.