Insect Systematics and Diversity

Zhao, Qing-Hao; Hansen, Aslak Kappel; Brunke, Adam; Tang, Liang; Solodovnikov, Alexey

doi: 10.1093/isd/ixag003pmid: N/A

We provide the first taxonomic revision of the rove beetle genus Platydracus of China, which includes 102 species currently known there and 6 species from neighboring countries that are highly likely to occur in China. The revision incorporates the recently updated, phylogeny-based concept of Platydracus and, DNA-grade material permitting, employs both morphology and COI barcode for species delimitation. Instead of using subgenera that did not prove to be monophyletic, we classified revised species of Platydracus in 13 mainly monophyletic species groups rooted in the global phylogenetic study of the Platydracus-group of genera. In this revision, we describe 61 species as new to science: Platydracus acutatissimus  sp. nov., Platydracus acutatus  sp. nov., Platydracus aerugineus  sp. nov., Platydracus alesi  sp. nov., Platydracus argentatus  sp. nov., Platydracus arnaudi  sp. nov., Platydracus asperatus  sp. nov., Platydracus atrovirens  sp. nov., Platydracus attenuatus  sp. nov., Platydracus aurarius  sp. nov., Platydracus biaureus  sp. nov., Platydracus binhongi  sp. nov., Platydracus bispeculosus  sp. nov., Platydracus brachelytrus  sp. nov., Platydracus brunneolus  sp. nov., Platydracus cinereus  sp. nov., Platydracus commutatus  sp. nov., Platydracus concavus  sp. nov., Platydracus cupreus  sp. nov., Platydracus dubius  sp. nov., Platydracus fangshuoi  sp. nov., Platydracus felis  sp. nov., Platydracus fluxilis  sp. nov., Platydracus glabrescens  sp. nov., Platydracus gladius  sp. nov., Platydracus grebennikovi  sp. nov., Platydracus hirsutus  sp. nov., Platydracus iridescens  sp. nov., Platydracus jani  sp. nov., Platydracus josei  sp. nov., Platydracus joshi  sp. nov., Platydracus lii  sp. nov., Platydracus longiusculus  sp. nov., Platydracus maculicrus  sp. nov., Platydracus maii  sp. nov., Platydracus martini  sp. nov., Platydracus megaparamerus  sp. nov., Platydracus michaeli  sp. nov., Platydracus minutus  sp. nov., Platydracus newtoni  sp. nov., Platydracus nonnemani  sp. nov., Platydracus nubis  sp. nov., Platydracus obscurus  sp. nov., Platydracus ocellatus  sp. nov., Platydracus profestus  sp. nov., Platydracus purpuronotus  sp. nov., Platydracus rotundatus  sp. nov., Platydracus rufitergus  sp. nov., Platydracus rufotibialis  sp. nov., Platydracus rugosus  sp. nov., Platydracus saevus  sp. nov., Platydracus schillhammeri  sp. nov., Platydracus scutiformis  sp. nov., Platydracus striolatus  sp. nov., Platydracus sumptuosus  sp. nov., Platydracus tigris  sp. nov., Platydracus trapeziformis  sp. nov.  Platydracus ultimus  sp. nov., Platydracus unicus  sp. nov., Platydracus variegatus  sp. nov., Platydracus vulpes  sp. nov. We establish 25 new synonyms as follows: Platydracus asemus (Kraatz, 1859) [=Platydracus subauronotatus Coiffait, 1977 syn. nov.], Platydracus auronotatus (Fauvel, 1895) [=Platydracus yunnanicus Smetana and Davies, 2000 syn. nov.], Platydracus basicornis (Fauvel, 1895) [=Staphylinus dohertyi (Cameron, 1932) syn. nov.], Platydracus bengalensis (Bernhauer, 1914) [=Platydracus aeneipennis (Cameron, 1930) syn. nov.], Platydracus brevicornis (Motschulsky, 1861) [=Platydracus consularis (Bernhauer, 1915) syn. nov.], Platydracus chalcescens (Sharp, 1889) [=Platydracus kiushiuensis (Bernhauer, 1939) syn. nov.], Platydracus chinensis (Bernhauer, 1914) [=Platydracus circumcinctus (Bernhauer, 1914) syn. nov., =Platydracus hauserianus (Bernhauer, 1933) syn. nov., =Platydracus plebejus (Bernhauer, 1915) syn. nov.], Platydracus collaris Coiffait, 1977 [=Platydracus perreaui (Coiffait, 1984) syn. nov.], Platydracus hewitti (Bernhauer, 1914) [=Platydracus kalisi (Bernhauer, 1934) syn. nov., =Platydracus preangeranus (Cameron, 1937) syn. nov.], Platydracus impotens (Eppelsheim, 1889) [=Platydracus oculosus (Smetana and Davies, 2000)  syn. nov.], Platydracus maculicollis (Fauvel, 1895) [=Platydracus borneensis Rougemont, 2015 syn. nov., =Platydracus patricius (Bernhauer, 1915) syn. nov.], Platydracus marmorellus (Fauvel, 1895) [=Platydracus fuscolineatus (Bernhauer, 1934) syn. nov.], Platydracus parvulus (Smetana and Davies, 2000) [=Platydracus masumotoi (Hayashi, Y. 2011) syn. nov.], Platydracus plagiicollis (Fairmaire, 1891) [=Platydracus associatus (Cameron, 1937) syn. nov., =Platydracus montanides (Newton, 2015)  syn. nov.], Platydracus pseudopaganus (Bernhauer, 1914) stat. nov. [=Platydracus becquarti (Bernhauer, 1938) syn. nov., =Platydracus formosae (Bernhauer, 1933) syn. nov., =Platydracus pseudopaganus pseudopatricius (Müller, 1926) syn. nov.], Platydracus sharpi (Fauvel, 1901) [=Platydracus pratti (Scheerpeltz, 1962) syn. nov.], and Platydracus virgulatus (Fauvel, 1895) [=Platydracus auroaeneus (Cameron, 1938) syn. nov., =Platydracus subviridis (Bernhauer, 1933) syn. nov.]. Fourteen previously named species are recorded for the Chinese fauna for the first time. To fix the definitions for 26 species, we designate lectotypes for: Platydracus aeneicollis (Bernhauer, 1911) (syn. of P. asemus (Kraatz, 1859)), P. asemus (Kraatz, 1859), P. associatus (Cameron, 1937), P. auronotatus (Fauvel, 1895), P. basicornis (Fauvel, 1895), Platydracus birmanus (Fauvel, 1895), P. chalcescens (Sharp, 1889), Platydracus curticornis (Fauvel, 1895), Platydracus decipiens (Kraatz, 1859), P. fuscolineatus (Bernhauer, 1934), Platydracus imperatorius (Bernhauer, 1916), Platydracus inornatus (Sharp, 1874), P. kalisi (Bernhauer, 1934), Platydracus kiulungensis (Bernhauer, 1933), P. maculicollis (Fauvel, 1895), P. marmorellus (Fauvel, 1895), Platydracus parvus (Cameron, 1932) (syn. of P. parvulus Smetana and Davies, 2000), P. plagiicollis (Fairmaire, 1891), P. pratti (Scheerpeltz, 1962), P. pseudopaganus pseudopatricius (Müller, 1926), Platydracus reitterianus (Bernhauer, 1933), P. sharpi (Fauvel, 1901), Platydracus speculifrons (Bernhauer, 1939), Platydracus subirideus (Kraatz, 1859), Platydracus vicarius (Sharp, 1889), and P. virgulatus (Fauvel, 1895). For all species, we provide diagnoses, distribution maps, and summarize their bionomics when available. For all new or poorly known species, we also give more detailed descriptions and comparisons. We open the descriptive part of the revision with a general account of Platydracus morphology and conclude it with the identification key to species hitherto recorded or very likely expected in China. The revision is richly illustrated and contains a succinct discussion of major findings and trends relevant for future study of this genus in China or beyond.

Liu, Jiuzhou; Cai, Xiaodong; Xiao, Yishen; Chen, Xulong; Cao, Wenqiang; Ding, Shuangmei; Zhan, Shuai; Li, Zhu; Yang, Ding

doi: 10.1093/isd/ixag020pmid: N/A

Sexual dimorphism is widespread in animals and often reflects evolutionary trade-offs between natural and sexual selection. Understanding the genomic and molecular mechanisms underlying these differences is key to revealing how adaptive traits evolve. Bibio rufiventris, commonly known as the fulvous-female march fly, exhibits striking sexual dimorphism, with males uniformly black and possessing enlarged compound eyes, while females display vivid reddish-orange thoraces and abdomens, making it an ideal model for investigating the genetic and molecular basis of sexually dimorphic traits. Here, we present a high-quality chromosome-level genome assembly of B. rufiventris. Comparative genomics revealed expansion of developmental and metabolic gene families in B. rufiventris, and branch-site analysis identified 265 positively selected genes, some of which are enriched in sensory-system development, including compound eye morphogenesis and multiple sensory perception processes. Transcriptomic profiling showed strong male-biased expression of phototransduction genes (eg ninaE, Arr2, and inaD) in heads, which may explain the enhanced visual processing capability in males. We also find a coordinated regulation pattern across melanin, pteridine, ommochrome, and heme–biliverdin pathways appears to underlie the female-specific coloration. These findings yield novel insights into sexual dimorphism in B. rufiventris in terms of pigment metabolism, visual system specialization, and sensory adaptation. This study also adds to our understanding of the genetic basis and evolutionary diversification of sexual traits in Bibionidae and other Diptera.

Li, Zhaoyi; Zhang, Chao; Zhang, Feng

doi: 10.1093/isd/ixag022pmid: N/A

The systematic status of the family Miturgidae Simon, 1886 and related subfamilies has long been problematic, primarily due to challenges in interpreting morphological characters and limited molecular sampling. In this study, we reconstruct the phylogeny of Miturgidae using ultraconserved elements and estimate its divergence time. Our results suggest that Systariinae does not belong to Miturgidae, but rather is sister to all other families of the Dionycha B clade. Consequently, we elevate it to family rank as Systariidae Deeleman-Reinhold, 2001 and discuss its morphological synapomorphies. Furthermore, our analyses place Miturgidae as the sister clade to Viridasiidae + Selenopidae under multiple phylogenetic methods. Divergence time estimates indicate an ancient origin of Systariidae in the Early Cretaceous (ca. 112 Ma), while Miturgidae appeared later during the Late Cretaceous (ca. 76 Ma). This study significantly advances the understanding of the phylogeny, systematics, and evolutionary history of Miturgidae and Systariidae, providing a robust foundation for future taxonomic and evolutionary research.

Weinrich, Christian L; Bubeníková, Kristýna; Sheikh, Sofia I; Steffensen, MaKella J; Ward, Anna K G; Zhang, Yuanmeng Miles; Forbes, Andrew A

doi: 10.1093/isd/ixag021pmid: N/A

Species discovery (inferring species limits de novo, without a priori hypotheses) from genetic data has become more common as molecular tools have expanded and has been a helpful initial step in tackling the taxonomic impediment for small insects. Often species discovery involves a single locus (eg mitochondrial cytochrome oxidase I [mtCOI]), but the accessibility of techniques for large sub-genomic sequencing projects (1000 s of loci) makes it possible to approach molecular species discovery with more robust datasets. Here, we test unsupervised machine learning (UML) methods for species discovery on a set of ultra-conserved element loci for a large collection of parasitic wasps reared from North American oak galls, all initially thought to be in genus Eurytoma Illiger. UML methods produced species hypotheses that largely aligned with those that emerge from a commonly used mtCOI-based species partitioning method, and that also tended to match existing species descriptions. Results revealed a new genus-level association with oak galls (Phylloxeroxenus Ashmead) hidden among the Eurytoma, 2 distinct lineages of Eurytoma, including a new lineage of Eurytoma more closely related to the South American genus Kavayva Zhang, Gates, and Silvestre, evidence for one or more cryptic Eurytoma species, and a mix of generalist and specialist host ranges. We make recommendations for how best to employ UML methods to similar datasets.

Zhang, Yaoyao; Li, Yanfei; Liang, Jingyu; Liu, Huaxi; Xue, Huaijun; Wang, Shujing; Bu, Wenjun

doi: 10.1093/isd/ixag023pmid: N/A

The genus Plautia (Hemiptera: Pentatomidae) encompasses multiple major agricultural pests, yet its taxonomy has long relied solely on morphological characters. This approach often overlooks cryptic species due to high morphological similarity, leading to taxonomic uncertainties. We used an integrative approach—combining morphological traits, mitochondrial data (13 protein-coding genes, COX1 barcodes), and nuclear Single Nucleotide Polymorphisms (SNPs) generated via double-digest restriction site-associated DNA sequencing to delimit Plautia species from China. Molecular phylogenies (Bayesian Inference/Maximum Likelihood) recovered 3 major clades within Chinese Plautia. Multi-method species delimitation (Automatic Barcode Gap Discovery, Assemble Species by Automatic Partitioning, Bayesian Poisson Tree Processes, Generalized Mixed Yule Coalescent, BPP, sparse non-negative matrix factorization, discriminant analysis of principal components, Bayes Factor Delimitation, hierarchical heuristic species delimitation) identified 10 distinct species, including 2 new species (Plautia xizangensis Zhang and Bu, sp. nov. from Xizang and Plautia bameiensis Zhang and Bu, sp. nov. from Yunnan), 1 new Chinese record (Plautia southwoodi), and 1 subspecies elevated to species (P. yunnanensis stat. nov.). Divergence time estimation linked the Oligocene diversification of Plautia to the uplift of the Hengduan Mountains, and Age-Range-Correlation analysis supported allopatric/parapatric speciation driven by geographic isolation and elevational niche differentiation. Our findings demonstrate the effectiveness of integrative taxonomy and multi-locus molecular data for precise species identification, especially in delimiting closely related taxa. Furthermore, this study provides new insights into the significant role of the uplift of the Hengduan Mountains in promoting speciation processes in the mountainous regions of southwestern China.