Evolutionary radiation strategy revealed in the Scarabaeidae with evidence of continuous spatiotemporal morphology and phylogenesis.

Evolutionary biology faces the important challenge of determining how to interpret the relationship between selection pressures and evolutionary radiation. The lack of morphological evidence on cross-species research adds to difficulty of this challenge. We proposed a new paradigm for evaluating the evolution of branches through changes in characters on continuous spatiotemporal scales, for better interpreting the impact of biotic/abiotic drivers on the evolutionary radiation. It reveals a causal link between morphological changes and selective pressures: consistent deformation signals for all tested characters on timeline, which provided strong support for the evolutionary hypothesis of relationship between scarabs and biotic/abiotic drivers; the evolutionary strategies under niche differentiation, which were manifested in the responsiveness degree of functional morphological characters with different selection pressure. This morphological information-driven integrative approach sheds light on the mechanism of macroevolution under different selection pressures and is applicable to more biodiversity research.

Taxonomic review of the genus Ponyalis Fairmaire, 1899 (Coleoptera, Lycidae), with descriptions of six new species from China.

The lycid genus Ponyalis Fairmaire, 1899 is reviewed. Six new species are described from China, including P.longicornis sp. nov., P.truncata sp. nov., P.dabieshanensis sp. nov., P.hainanensis sp. nov., P.quadricollimima sp. nov., and P.zhejiangensis sp. nov. Nine previously known species, including P.alternata (Pic, 1927), P.fukiensis (Bocak, 1999), P.gracilis (Bocak, 1999), P.himalejica (Bourgeois, 1885), P.klapperichi (Bocak, 1999), P.laticornis Fairmaire, 1899, P.nigrohumeralis (Pic, 1939), P.quadricollis (Kiesenwetter, 1874), and P.variabilis Li, Bocak & Pang, 2015 are illustrated with images of the habitus and aedeagi to make the comparisons with the new species. In addition, a distribution map and an identification key to all 24 species of Ponyalis are provided.

A review of the leaf-beetle genus Sinoluperus Gressitt & Kimoto, 1963 (Coleoptera, Chrysomelidae, Galerucinae) from China, with the description of a new species.

In this study, all species of the leaf-beetle genus Sinoluperus Gressitt & Kimoto, 1963 from China are redescribed based on the reexamination of type specimens, and a new species, S.variegatussp. nov. from Nanling Mountains, is described. A key to the three Chinese species of Sinoluperus is provided, as well as photographs of the habiti and aedeagi of these species.

A new Chinese Cyclogethes pollen beetle, with an updated key to species of the genus and notes on its phylogenetic positioning (Coleoptera: Nitidulidae: Meligethinae).

A peculiar new species of the genus Cyclogethes Kirejtshuk, 1979, C. tibialis sp. nov., is described from Southwestern China (Yunnan). The new species appears to be morphologically rather isolated from the other known members of this essentially Oriental genus (including half a dozen species from Northern Indian subcontinent, Northern Indochina, and Southwestern China). However, it could be more closely related to C. abnormis Kirejtshuk, 1979 from Northern India, Indochina, and Southwestern China, and to C. aldridgei Kirejtshuk, 1980 from Northern India and Nepal, from which it is easily distinguished by the more elongate body shape, and by the markedly sinuate hind tibiae in both sexes (a very unusual character state in Meligethinae, where only males of some species exhibit sexual secondary characters in the tibial shape). The new species also differs from other known taxa of the genus by the shape of the male and female genitalia. The larval hostplants of members of Cyclogethes are thus far unknown, although some clues, also involving the new species described herein, may suggest a relationship with small trees or shrubs of the family Asteraceae. Preliminary and incomplete molecular data on a studied member of the genus (C. abnormis) seems to not disagree with a phylogenetic positioning of Cyclogethes in a clade including the African genera Tarchonanthogethes Audisio & Cline, 2009, its allied Afrotropical taxa, and the Palaearctic genera Meligethes Stephens, 1830 and Brassicogethes Audisio & Cline, 2009. The article includes an updated identification key for all six known species of this genus and an updated map of their known geographic distribution.

A taxonomic study on the nominate subgenus Macrolycus Waterhouse, 1878 from China (Coleoptera, Lycidae).

In the present study, a new species of Macrolycus s. str. is reported from China and described as M. subapicis sp. nov. M. bowringi Waterhouse, 1878 is recorded to China for the first time. The above two species, M. oreophilus Kazantsev, 2002 and M. gansuensis Kazantsev, 2002 are illustrated with the male habitus and genitalia. In addition, a distribution map, and a key to the species of Macrolycus s. str. in the world are provided.

A Review of Chinese Species of the Genus Oides Weber, 1801 (Coleoptera: Chrysomelidae: Galerucinae).

In this study, 25 species of Oides Weber from China were reviewed. Among them, the following seven new species are described: Oides angustasp. nov., O. cystoprocessasp. nov., O. paraborerisp. nov., O. parabowringiisp. nov., O. parathibettanasp. nov., O. shimenensissp. nov., and O. yunnanensissp. nov.; Oides innocua Gahan has been recorded in China for the first time. A key to all the Chinese Oides species is provided.

Characterization of Four Complete Mitogenomes of Monolepta Species and Their Related Phylogenetic Implications.

Monolepta is one of the diverse genera in the subfamily Galerucinae, including 708 species and 6 sub-species worldwide. To explore the information on the mitogenome characteristics and phylogeny of the section "Monoleptites", especially the genus Monolepta, we obtained the newly completed mitochondrial genomes (mitogenomes) of four Monolepta species using high-throughput sequencing technology. The lengths of these four new mitochondrial genomes are 16,672 bp, 16,965 bp, 16,012 bp, and 15,866 bp in size, respectively. All four mitochondrial genomes include 22 transfer RNA genes (tRNAs), 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNAs), and one control region, which is consistent with other Coleoptera. The results of the nonsynonymous with synonymous substitution rates showed that ND6 had the highest evolution rate, while COI displayed the lowest evolution rate. The substitution saturation of three datasets (13 PCGs_codon1, 13 PCGs_codon2, 13 PCGs_codon3) showed that there was no saturation across all datasets. Phylogenetic analyses based on three datasets (ND1, 15 genes of mitogenomes, and 13 PCGs_AA) were carried out using maximum likelihood (ML) and Bayesian inference (BI) methods. The results showed that mitogenomes had a greater capacity to resolve the main clades than the ND1 gene at the suprageneric and species levels. The section "Monoleptites" was proven to be a monophyletic group, while Monolepta was a non-monophyletic group. Based on ND1 data, the newly sequenced species whose antennal segment 2 was shorter than 3 were split into several clades, while, based on the mitogenomic dataset, the four newly sequenced species had close relationships with Paleosepharia. The species whose antennal segment 2 was as long as 3 were split into two clades, which indicated that the characteristic of "antennal segment 2 as long as 3" of the true "Monolepta" evolved multiple times in several subgroups. Therefore, to explore the relationships among the true Monolepta, the most important thing is to perform a thorough revision of Monolepta and related genera in the future.

Review of the Lycoceruspallidulus group (Coleoptera, Cantharidae), with descriptions of six new species from China.

The Lycoceruspallidulus subgroup, originally placed in the L.maculicollis group, is suggested as an independent species group herein and its diagnosis is redefined. Ten previously known species of Lycocerus are attributed to this group, including L.centrochinensis (Svihla, 2004), L.genaemaculatus (Wittmer, 1951), L.hubeiensis (Svihla, 2004), L.kubani (Svihla, 2004), L.zdeneki (Svihla, 2004), L.bilineatus (Wittmer, 1995), L.jelineki (Svihla, 2004), L.putzi Svihla, 2011, L.pictipennis (Wittmer, 1995), and L.curvatus (Wittmer, 1995). Additionally, six new species of this group are described from China, including L.laterophysussp. nov., L.flavipennissp. nov., L.putzimimussp. nov., L.maoershanensissp. nov., L.chongqingensissp. nov., and L.bispermathecussp. nov. These species are illustrated with photographs of habitus, aedeagi, abdominal sternites VIII, and reproductive systems of female. In addition, an identification key and a distribution map of the L.pallidulus group are provided.

Revision of Aplosonyx Chevrolat, 1836 (Coleoptera, Chrysomelidae, Galerucinae) from China, with descriptions of three new species.

In this study, 21 species of the leaf-beetle genus Aplosonyx in China are described, including three new species, Aplosonyxancorellasp. nov., Aplosonyxnigricornissp. nov. and Aplosonyxwudangensissp. nov., and 1 new record, Aplosonyxduvivieri Jacoby, 1900. Additionally, Aplosonyxancorafulvescens Chen, 1964 is elevated to species. A key to the Chinese species of Aplosonyx is provided.

A Cretaceous Chafer Beetle (Coleoptera: Scarabaeidae) with Exaggerated Hind Legs-Insight from Comparative Functional Morphology into a Possible Spring Movement.

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.

A Phylogenetic Morphometric Investigation of Interspecific Relationships of Lyponia s. str. (Coleoptera, Lycidae) Based on Male Genitalia Shapes.

The nominate subgenus Lyponia Waterhouse, 1878 from China is reviewed, with two new species described and named L. (s. str.) ruficeps sp. n. (China, Yunnan) and L. (s. str.) zayuana sp. n. (China, Xizang). A distribution map and a key to all species of Lyponia s. str. are provided. Moreover, the phenotypic relationships among the species of Lyponia s. str. are investigated based on phallus shapes using geometric morphometric and phylogenetic morphometric analyses. The topologies demonstrate that the species are divided into two clades. One clade is composed of six species (L. ruficeps sp. n., L. zayuana sp. n., L. kuatunensis, L. shaanxiensis, L. hainanensis, and L. tamdaoensis) and is supported by a stout phallus (less than 3.6 times longer than wide). The other clade includes the remaining species (L. nepalensis, L. debilis, L. cangshanica, L. delicatula, and L. oswai) and is supported by a slender phallus (at least 4.1 times longer than wide). These results provide better understanding of the species diversity and evolution of Lyponia s. str. Nonetheless, more samples and loci are required in the future to verify the present results.

Unexpected High Species Diversity of Mesolycus Gorham (Coleoptera, Lycidae) from China, with a Preliminary Investigation on Its Phylogenetic Position Based on Multiple Genes.

The lycid genus Mesolycus Gorham, 1883 is mainly distributed in East Palaearctic and Indochinese regions, but poorly studied in China; moreover, its phylogenetic placement remains controversial but has never been rigorously tested. In this study, Mesolycus was reviewed and its placement within Lycidae was tested based on a multilocus phylogeny (cox1, nad5, cox2 and Lrna) by both ML and BI analyses. The reconstructed phylogenies show that Mesolycus is a consistently recovered sister to Dilophotes Waterhouse, 1879, and they form a monophyletic clade which is well supported. This suggests that Mesolycus definitely belongs to Dilophotini rather than to Macrolycini of Lycinae. Besides, three species originally described or placed in Dilophotes are transferred to Mesolycus, including M. atricollis (Pic, 1926) comb. n., M. particularis (Pic, 1928) comb. n. and M. pacholatkoi (Bic, 2002) comb. n. Four new species are discovered in China, including M. shaanxiensis sp. n., M. dentatus sp. n., M. breviplatus sp. n. and M. varus sp. n. Two species, M. murzini Kazantsev, 2004 and M. rubromarginatus Kazantsev, 2013, are recorded from China for the first time. A key for the identification of all Mesolycus species is provided. China was revealed as the region with the highest species diversity of this genus.

Complete mitochondrial genome of Distenia punctulatoides (Coleoptera: Chrysomeloidea: Disteniinae) and its phylogenetic implications.

The family Disteniidae is a moderately large and widely distributed lineage. Distenia punctulatoides belongs to the family Disteniidae from the cerambycoid assemblage. Here, we report the complete mitogenome of D. punctulatoides, which is 15,675 bp in length. It contains 37 genes and a noncoding control region, which are arranged in the same order as that of the putative ancestor of beetles. The total base composition of the new mitogenome is 40.2% for A, 17.1% for C, 10.0% for G, and 32.7% for T. The new mitogenomic organization, nucleotide composition, and codon usage do not differ significantly from other beetles. Using available complete mitogenomes, the high-level phylogeny of the family Disteniidae was explored. The phylogenetic analyses showed that Disteniidae were monophyletic, and the genus Distenia grouped with the genus Clytomelegena as sister groups. Combining the morphological and molecular data, Typodryas Thomson, 1864 is suggested to be a junior synonym of Distenia Lepeletier and Audinet-Serville, 1828.

Parallel metatranscriptome analysis reveals degradation of plant secondary metabolites by beetles and their gut symbionts.

Switching to a new host plant is a driving force for divergence and speciation in herbivorous insects. This process of incorporating a novel host plant into the diet may require a number of adaptations in the insect herbivores that allow them to consume host plant tissue that may contain toxic secondary chemicals. As a result, herbivorous insects are predicted to have evolved efficient ways to detoxify major plant defences and increase fitness by either relying on their own genomes or by recruiting other organisms such as microbial gut symbionts. In the present study we used parallel metatranscriptomic analyses of Altica flea beetles and their gut symbionts to explore the contributions of beetle detoxification mechanisms versus detoxification by their gut consortium. We compared the gut meta-transcriptomes of two sympatric Altica species that feed exclusively on different host plant species as well as their F1 hybrids that were fed one of the two host plant species. These comparisons revealed that gene expression patterns of Altica are dependent on both beetle species identity and diet. The community structure of gut symbionts was also dependent on the identity of the beetle species, and the gene expression patterns of the gut symbionts were significantly correlated with beetle species and plant diet. Some of the enriched genes identified in the beetles and gut symbionts are involved in the degradation of secondary metabolites produced by plants, suggesting that Altica flea beetles may use their gut microbiota to help them feed on and adapt to their host plants.

A species diversity dataset of beetles by three passive acquisition methods in Tei Tong Tsai (Hong Kong).

We based the dataset in this paper on the beetle collection from the sample site of Tei Tong Tsai (Hong Kong) from 1st May to 28th May 2019, a period of high insect diversity. A total of 16,270 beetles (photographed in 318 images) from 478 species belonging to 39 families were collected. The dataset consists of the following components: The original photo of the whole sample obtained at each site with each collection method, the morphological species identification chart, a statistical table describing the species and numbers of beetles collected on different dates at different sites using three passive acquisition methods, and a statistical table describing the longitude, latitude, and altitude information of each sampling point. We aimed to provide a database for the evaluation of beetle species diversity in Hong Kong and a paradigm for the effectiveness of passive acquisition in the beetle collection through the three representative methods, thus laying a foundation for biodiversity research.

Functional Morphology of the Thorax of the Click Beetle Campsosternus auratus (Coleoptera, Elateridae), with an Emphasis on Its Jumping Mechanism.

We investigated and described the thoracic structures, jumping mechanism, and promesothoracic interlocking mechanism of the click beetle Campsosternus auratus (Drury) (Elateridae: Dendrometrinae). Two experiments were conducted to reveal the critical muscles and sclerites involved in the jumping mechanism. They showed that M2 and M4 are essential clicking-related muscles. The prosternal process, the prosternal rest of the mesoventrite, the mesoventral cavity, the base of the elytra, and the posterodorsal evagination of the pronotum are critical clicking-related sclerites. The destruction of any of these muscles and sclerites resulted in the loss of normal clicking and jumping ability. The mesonotum was identified as a highly specialized saddle-shaped biological spring that can store elastic energy and release it abruptly. During the jumping process of C. auratus, M2 contracts to establish and latch the clicking system, and M4 contracts to generate energy. The specialized thoracic biological springs (e.g., the prosternum and mesonotum) and elastic cuticles store and abruptly release the colossal energy, which explosively raises the beetle body in a few milliseconds. The specialized trigger muscle for the release of the clicking was not found; our study supports the theory that the triggering of the clicking is due to the building-up of tension (i.e., elastic energy) in the system.

Revision of Sphenoraia Clark, 1865 (Coleoptera, Chrysomelidae, Galerucinae) from China, with descriptions of two new species.

In this study, ten species of Sphenoraia Clack, 1865 are recognized and re-described: Sphenoraia (Sphenoraioides) anjiensis Yang & Li, 1998, Sphenoraia (Sphenoraioides) berberii Jiang, 1992, Sphenoraia (Sphenoraioides) duvivieri (Laboissière, 1925), Sphenoraia (Sphenoraioides) haizhuensis Yang, 2021, Sphenoraia (Sphenoraioides) micans (Fairmaire, 1888), Sphenoraia (Sphenoraioides) nebulosa (Gyllenhal, 1808), Sphenoraia (Sphenoraioides) nigromaculata Jiang, 1992, Sphenoraia (Sphenoraioides) punctipennis Jiang, 1992, Sphenoraia (Sphenoraioides) rutilans (Hope, 1831), and Sphenoraia (Sphenoraioides) yajiangensis Jiang, 1992. Two new species, Sphenoraia (Sphenoraia) decemmaculata Feng, Yang & Liu, sp. nov. and Sphenoraia (Sphenoraioides) flavomarginata Feng, Yang & Li, sp. nov., are described. Additionally, Sphenoraia (Sphenoraia) cupreata Jacoby, 1890 and Sphenoraia (Sphenoraia) nigra Wang, Li & Yang, 2000 are transferred from Sphenoraia to Gallerucida. A key to the 12 Chinese species of Sphenoraia is given.

Notes on spotted-elytron species of Gallerucida Motschulsky with the description of six new species from China (Coleoptera, Chrysomelidae, Galerucinae).

In this study, fifteen species of Gallerucida Motschulsky, 1860 (Coleoptera: Chrysomelidae: Galerucinae), with spotted elytra, from China are reviewed, including one new record: G.balyi (Duvivier, 1885), six new species: G.fortispina Xu & Yang, sp. nov., G.levifasciata Xu & Nie, sp. nov., G.nigrovittata Xu & Yang, sp. nov., G.octodecimpunctata Xu & Yang, sp. nov., G.piceusfasciata Xu & Yang, sp. nov., G.rufipectoralis Xu & Nie, sp. nov., and Aplosonyxgansuica (Chen, 1942), comb. nov. is removed from genus Gallerucida. A key to the spotted-elytron species of Gallerucida from China is given as well as habitus photographs of the related species and Aplosonyxgansuica comb. nov. and photographs of the aedeagus of each new species.

Definitions of two species groups of Stenothemus Bourgeois (Coleoptera, Cantharidae), with descriptions of three new species from China.

Two new species-groups of the cantharid genus Stenothmeus Bourgeois are defined, S. laterophysus species-group and S. notaticollis species-group. The S. laterophysus species-group is composed of two species, including S. laterophysus vihla, 2004 and a new species, S. nigritibius Y. Yang et H. Liu, sp. nov., and characterized by the pitch black elytra and bicolored legs, the subrounded pronotum with widely rounded anterior angles and projecting posterior angles, male genitalia with slender ventral processes of parameres which are slightly bent inwards at apical parts, laterophyses tilting ventrally at an angle of more than 45 with dorsal plates, compressed at apical parts, as well as the slender spermathecal duct, extremely long spermatheca and diverticulum. The S. notaticollis species-group consists of five species, including S. notaticollis (Gorham, 1895), S. bourgeoisi Wittmer, 1974, S. tamil vihla, 2011 and two new species, S. parameratus Y. Yang et S. Ge, sp. nov. and S. acutiapicis Y. Yang et X. Yang, sp. nov., which is differentiated from the S. laterophysus species-group by the more variable body coloration, elytra pitch black or black brown or pale-yellow, male genitalia with thick or flattened ventral processes of parameres which are diverging apically, laterophyses parallel to dorsal plates, expanded at apices, as well as the stout spermathecal duct, moderately long spermatheca and diverticulum. The above species are illustrated with photographs of habitus, male genitalia, abdominal sternites and internal genitalia of female. A key for the identification of these species is provided and a distribution map is presented.