Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 70
Filter
1.
Methods Mol Biol ; 2744: 33-52, 2024.
Article in English | MEDLINE | ID: mdl-38683310

ABSTRACT

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.


Subject(s)
DNA , DNA/genetics , DNA Barcoding, Taxonomic/methods , Classification/methods , Phylogeny , Species Specificity
2.
Zootaxa ; 5406(1): 141-152, 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-38480160

ABSTRACT

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.


Subject(s)
Coleoptera , Animals , Laos , Vietnam
3.
Zootaxa ; 5418(5): 442-470, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38480345

ABSTRACT

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.


Subject(s)
Coleoptera , Animals
4.
Mol Ecol Resour ; 24(3): e13921, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38146909

ABSTRACT

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.


Subject(s)
Butterflies , Animals , Phylogeny , Butterflies/genetics , DNA , Genome , Hybridization, Genetic
5.
Zookeys ; 1185: 181-198, 2023.
Article in English | MEDLINE | ID: mdl-38074903

ABSTRACT

In this paper we update the knowledge on the species of Serica McLeay, 1819 (sensu lato) occurring in Yunnan, Sichuan, and Shaanxi provinces, China. Three new species are described: Sericaallonanhua Liu, Ahrens, Li & Su, sp. nov., S.breviantennalis Liu, Ahrens, Li & Su, sp. nov., and S.fengensis Liu, Ahrens, Li & Su, sp. nov. The key to the species groups and species is updated. The habitus and male genitalia of the new species are illustrated, and a map showing their distribution is provided. New distributional data are given for four species.

6.
Ecol Evol ; 13(5): e10091, 2023 May.
Article in English | MEDLINE | ID: mdl-37187965

ABSTRACT

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.

7.
Zootaxa ; 5241(1): 1-115, 2023 Feb 14.
Article in English | MEDLINE | ID: mdl-37044486

ABSTRACT

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.


Subject(s)
Coleoptera , Animals , Asia
9.
Biology (Basel) ; 12(2)2023 Feb 02.
Article in English | MEDLINE | ID: mdl-36829514

ABSTRACT

The phenomenon of exaggerated morphological structures has fascinated people for centuries. Beetles of the family Scarabaeidae show many very diverse exaggerated characters, for example, a variety of horns, enlarged mandibles or elongated antennal lamellae. Here, we report a new Mesozoic scarab, Antiqusolidus maculatus gen. et sp. n. from the Lower Cretaceous Yixian Formation (~125 Ma), which has unusually robust and structured hind legs with greatly enlarged spurs and a unique elongated apical process. Based on simulations and finite element analyses, the function of these structures is hypothesized to support springing to aid movement and fighting. Based on available morphological characters, we performed phylogenetic analyses (maximum parsimony) of the main subfamilies and families of Scarabaeoidea. The results support the placement of Antiqusolidus gen. n. as a sister group of Rutelinae within the phytophagous lineage of pleurostict Scarabaeidae. Furthermore, the unusual delicate color marking patterns in the fossil specimens suggest that the new species might have been diurnal and potentially visited the leaves or flowers of Early Cretaceous plants. This morphological and functional study on this extinct scarab species provides new sights into exaggerated structures in Mesozoic insects.

10.
Zootaxa ; 5353(4): 351-371, 2023 Oct 11.
Article in English | MEDLINE | ID: mdl-38220679

ABSTRACT

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.


Subject(s)
Coleoptera , Animals , India , Zoology
11.
Zootaxa ; 5361(2): 181-220, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-38220765

ABSTRACT

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.


Subject(s)
Coleoptera , Animals , China
12.
Zootaxa ; 5374(4): 451-486, 2023 Nov 20.
Article in English | MEDLINE | ID: mdl-38220848

ABSTRACT

An update to the taxonomy and distribution of species of Tetraserica Ahrens, 2004 (Coleoptera: Scarabaeidae) is given. We present new records of 36 taxa and describe 13 new species from continental Southeast Asia: Tetraserica bartolozzii Ahrens, new species, T. bankrang Ahrens, new species, T. sraeken Ahrens, new species, T. yongbelar Ahrens, new species, T. hubleyi Ahrens, new species, T. hornburgi Ahrens, new species, T. khemoi Ahrens, new species, T. weigeli Ahrens, new species, T. yucheni Liu, Li & Ahrens, new species, T. fabriziae Liu, Li & Ahrens, new species, T. gialaiensis Pham & Ahrens, new species, T. phamanhi Pham & Ahrens, new species, and T. semikontumensis Pham & Ahrens, new species. The male genitalia of the new species are illustrated and diagnostic characters to related species are given. The key to species of continental Southeast Asia is updated.


Subject(s)
Coleoptera , Male , Animals , Genitalia, Male , Asia, Southeastern
13.
Zootaxa ; 5346(5): 551-566, 2023 Sep 21.
Article in English | MEDLINE | ID: mdl-38221323

ABSTRACT

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)).


Subject(s)
Coleoptera , Animals , Coleoptera/classification
14.
Ecol Evol ; 12(12): e9650, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36568864

ABSTRACT

DNA barcoding has been used worldwide to identify biological specimens and to delimit species. It represents a cost-effective, fast, and efficient way to assess biodiversity with help of the public Barcode of Life Database (BOLD) accounting for more than 236,000 animal species and more than 10 million barcode sequences. Here, we performed a meta-analysis of available barcode data of central European Coleoptera to detect intraspecific genetic patterns among ecological groups in relation to geographic distance with the aim to investigate a possible link between infraspecific variation and species ecology. We collected information regarding feeding style, body size, as well as habitat and biotope preferences. Mantel tests and two variants of Procrustes analysis, both involving the Principal Coordinates Neighborhood Matrices (PCNM) approach, were applied on genetic and geographic distance matrices. However, significance levels were too low to further use the outcome for further trait investigation: these were in mean for all ecological guilds only 7.5, 9.4, or 15.6% for PCNM + PCA, NMDS + PCA, and Mantel test, respectively, or at best 28% for a single guild. Our study confirmed that certain ecological traits were associated with higher species diversity and foster stronger genetic differentiation. Results suggest that increased numbers of species, sampling localities, and specimens for a chosen area of interest may give new insights to explore barcode data and species ecology for the scope of conservation on a larger scale. We performed a meta-analysis of available barcode data of central European beetles to detect intraspecific genetic patterns among ecological groups in relation to geographic distance, regarding feeding style, body size, as well as habitat and biotope preferences. Our study confirmed that certain ecological traits were associated with higher species diversity and foster stronger genetic differentiation. However, significance levels were too low to further use the outcome for further trait investigation.

16.
Zootaxa ; 5165(2): 180-190, 2022 Jul 14.
Article in English | MEDLINE | ID: mdl-36095473

ABSTRACT

In this paper, additional new species of Gynaecoserica Brenske, 1897 and the Neoserica calva group from continental Southeast Asia are described: Gynaecoserica krausi Ahrens, new species (Laos), G. obfuscata Ahrens, new species (Laos), Neoserica champassakensis Ahrens, new species (Laos), N. fairyqueen Ahrens, new species (Thailand), and N. samuelsoni Ahrens, new species (Laos). The habitus as well as the aedeagus of the new species are illustrated. New records of further species of the two genera are given.


Subject(s)
Coleoptera , Animals
17.
Ecol Evol ; 12(5): e8942, 2022 May.
Article in English | MEDLINE | ID: mdl-35600695

ABSTRACT

DNA taxonomy including barcoding and metabarcoding is widely used to explore the diversity in biodiversity hotspots. In most of these hotspot areas, chafers are represented by a multitude of species, which are well defined by the complex shape of male genitalia. Here, we explore how well COI barcode data reflect morphological species entities and thus their usability for accelerated species inventorization. We conducted dedicated field surveys in Sri Lanka to collect the species-rich and highly endemic Sericini chafers (Coleoptera: Scarabaeidae). Congruence among results of a series of protocols for de novo species delimitation and with morphology-based species identifications was investigated. Different delimitation methods, such as the Poisson tree processes (PTP) model, Statistical Parsimony Analysis (TCS), Automatic Barcode Gap Discovery (ABGD), Assemble Species by Automatic Partitioning (ASAP), and Barcode Index Number (BIN) assignments, resulted in different numbers of molecular operational taxonomic units (MOTUs). All methods showed both over-splitting and lumping of morphologically identified species. Only 18 of the observed 45 morphospecies perfectly matched MOTUs from all methods. The congruence of delimitation between MOTUs and morphospecies expressed by the match ratio was low, ranging from 0.57 to 0.67. TCS and multirate PTP (mPTP) showed the highest match ratio, while (BIN) assignment resulted in the lowest match ratio and most splitting events. mPTP lumped more species than any other method. Principal coordinate analysis (PCoA) on a match ratio-based distance matrix revealed incongruent outcomes of multiple DNA delimitation methods, although applied to the same data. Our results confirm that COI barcode data alone are unlikely to correctly delimit all species, in particular, when using only a single delimitation approach. We encourage the integration of various approaches and data, particularly morphology, to validate species boundaries.

19.
Zootaxa ; 5186(1): 1-83, 2022 Sep 13.
Article in English | MEDLINE | ID: mdl-37044813

ABSTRACT

In this paper we revised the species of Serica McLeay, 1819 (sensu lato) occurring in China an adjacent areas, and provide an update on the genus Nipponoserica Nomura, 1972. The revision resulted in one new combination: Serica adspersa (Frey, 1972), new combination. Thirty-nine new species are described: Nipponoserica daqiao Ahrens, Fabrizi & Liu, new species, Serica allolongipes Ahrens, Fabrizi & Liu, new species, S. allotengchongana Ahrens, Fabrizi & Liu, new species, S. baishuitaiensis Ahrens, Fabrizi & Liu, new species, S. baoshan Ahrens, Fabrizi & Liu, new species, S. daqiaoana Ahrens, Fabrizi & Liu, new species, S. dissimillima Ahrens, Fabrizi & Liu, new species, S. emaw Ahrens, Fabrizi & Liu, new species, S. gaoligong Ahrens, Fabrizi & Liu, new species, S. guangnanensis Ahrens, Fabrizi & Liu, new species, S. hailuogou Ahrens, Fabrizi & Liu, new species, S. huangbaiyuanensis Ahrens, Fabrizi & Liu, new species, S. huangjing Ahrens, Fabrizi & Liu, new species, S. jani Ahrens, Fabrizi & Liu, new species, S. jaroslavi Ahrens, Fabrizi & Liu, new species, S. jiankouensis Ahrens, Fabrizi & Liu, new species, S. jirii Ahrens, Fabrizi & Liu, new species, S. kuankuoshuiensis Ahrens, Fabrizi & Liu, new species, S. limbourgi Ahrens, Fabrizi & Liu, new species, S. longipes longipes Ahrens, Fabrizi & Liu, new species, S. longwang Ahrens, Fabrizi & Liu, new species, S. mengsongana Ahrens, Fabrizi & Liu, new species, S. nanhua Ahrens, Fabrizi & Liu, new species, S. pangwa Ahrens, Fabrizi & Liu, new species, S. paralongipes Ahrens, Fabrizi & Liu, new species, S. paralupina Ahrens, Fabrizi & Liu, new species, S. pseudogracilipes Ahrens, Fabrizi & Liu, new species, S. shengtangshan Ahrens, Fabrizi & Liu, new species, S. shiduensis Ahrens, Fabrizi & Liu, new species, S. smetanai Ahrens, Fabrizi & Liu, new species, S. taishun Ahrens, Fabrizi & Liu, new species, S. tengchongana Ahrens, Fabrizi & Liu, new species, S. tianmushan Ahrens, Fabrizi & Liu, new species, S. tianpingshanensis Ahrens, Fabrizi & Liu, new species, S. yini Ahrens, Fabrizi & Liu, new species, S. yuheba Ahrens, Fabrizi & Liu, new species, S. zhenba Ahrens, Fabrizi & Liu, new species, S. ziqingi Ahrens, Fabrizi & Liu, new species. A key to species groups and species within groups is given, habitus and male genitalia of the revised species are illustrated. The distribution of the species revised herein is shown on maps. New distributional data are given for sixteen species.


Subject(s)
Coleoptera , Male , Animals , China
20.
Syst Biol ; 71(2): 320-333, 2022 02 10.
Article in English | MEDLINE | ID: mdl-34143222

ABSTRACT

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.].


Subject(s)
Butterflies , Algorithms , Animals , Bees , Machine Learning , Neural Networks, Computer , Phylogeny
SELECTION OF CITATIONS
SEARCH DETAIL
...