Mitochondrial genome data provide insights into the phylogenetic relationships within Triplophysadalaica (Kessler, 1876) (Cypriniformes, Nemacheilidae).

Due to the detrimental effect of formaldehyde on DNA, ethanol has replaced formalin as the primary preservative for animal specimens. However, short-term formalin fixation of specimens might be applied during field collection. In an increasing number of studies, DNA extraction and sequencing have been successfully conducted from formalin-fixed specimens. Here the DNA from five specimens of Triplophysadalaica (Kessler, 1876) were extracted and performed high-throughput sequencing. Four of the specimens underwent short-term fixation with formalin and were subsequently transferred to ethanol. One was continuously stored in ethanol. No significant difference of DNA quality and amount were observed among these samples. Followed by assembly and annotation, five mitochondrial genomes ranging in length from 16,569 to 16,572 bp were obtained. Additionally, previously published data of other individuals or species were included to perform phylogenetic analyses. In the reconstructed trees, all eight individuals of T.dalaica form a monophyletic group within the Triplophysa branch. The group is divided into three clades: (1) samples from the Yellow River, (2) those from the Yangtze River, and (3) those from the Haihe River, and the Lake Dali Nur. This study sheds initial light on the phylogeographic relationships among different populations of T.dalaica, and will support the research about its evolutionary history in the future.

A review of the semipunctata species group within the genus Lilioceris Reitter, 1913 (Coleoptera, Chrysomelidae).

A new species group of Lilioceris Reitter, 1913 is proposed and reviewed, the semipunctata group. It includes eleven species: L.atrilateralis Kimoto & Takizawa, 1973, L.consentanea (Lacordaire, 1845), L.dentifemoralis Long, 1988, L.discrepens (Baly, 1879), L.jianfenglingensis Long, 1988, L.latissima (Pic, 1932), L.lianzhouensis Long, 2000a, L.rondoni Kimoto & Gressitt, 1979, L.rufometallica (Pic, 1923), L.semipunctata (Fabricius, 1801), and L.yuae Long, 2000b. Liliocerisdiscrepens and L.rondoni were new records from China. Two synonyms are proposed: Liliocerisxinglongensis Long, 1988, syn. nov. of L.consentanea (Lacordaire, 1845), and Criocerisrufimembris Pic, 1921, syn. nov. of L.semipunctata. An identification key, descriptions, habitus photographs, geographic distributions, host plants and habitats (if available), are provided for these species.

Leaf-feeding species of the genus Liothrips from China (Thysanoptera, Phlaeothripinae).

The 250 species of the second largest genus of Thysanoptera, Liothrips, are known as feeding mainly on green leaves, with many inducing galls or associated with galls. In China, 33 species are recognized including L. brevis sp. n., L. elongatus sp. n., L. longistylus sp. n., L. motuoensis sp. n., L. piceae sp. n., L. populi sp. n. and L. tibetanus sp. n., also seven species are recorded from this country for the first time. Four Hans Liothrips species are considered as new synonymies of L. vaneeckei that might be widespread in the Holarctic region. Three species are newly combined as Liothrips aporosae comb.n., Teuchothrips fuscus comb.n. and T. turkestanicus comb.n. The illustrated identification key to Chinese Liothrips species excludes L. hsuae but includes L. mirabilis due to its potential as a pest of Piper plants are growing throughout Southern China. Biology, structural variation, and generic relationships are also discussed.

Geographical patterns and determinants of insect biodiversity in China.

Insects play important roles in the maintenance of ecosystem functioning and the provision of livelihoods for millions of people. However, compared with terrestrial vertebrates and angiosperms, such as the giant panda, crested ibis, and the metasequoia, insect conservation has not attracted enough attention, and a basic understanding of the geographical biodiversity patterns for major components of insects in China is lacking. Herein, we investigated the geographical distribution of insect biodiversity across multiple dimensions (taxonomic, genetic, and phylogenetic diversity) based on the spatial distribution and molecular DNA sequencing data of insects. Our analysis included 18 orders, 360 families, 5,275 genera, and 14,115 species of insects. The results revealed that Southwestern and Southeastern China harbored higher insect biodiversity and numerous older lineages, representing a museum, whereas regions located in Northwestern China harbored lower insect biodiversity and younger lineages, serving as an evolutionary cradle. We also observed that mean annual temperature and precipitation had significantly positive effects, whereas altitude had significantly negative effects on insect biodiversity in most cases. Moreover, cultivated vegetation harbored the highest insect taxonomic and phylogenetic diversity, and needleleaf and broadleaf mixed forests harbored the highest insect genetic diversity. These results indicated that human activities may positively contribute to insect spatial diversity on a regional scale. Our study fills a knowledge gap in insect spatial diversity in China. These findings could help guide national-level conservation plans and the post-2020 biodiversity conservation framework.

Phylosymbiosis: The Eco-Evolutionary Pattern of Insect-Symbiont Interactions.

Insects harbor diverse assemblages of bacterial and fungal symbionts, which play crucial roles in host life history. Insects and their various symbionts represent a good model for studying host-microbe interactions. Phylosymbiosis is used to describe an eco-evolutionary pattern, providing a new cross-system trend in the research of host-associated microbiota. The phylosymbiosis pattern is characterized by a significant positive correlation between the host phylogeny and microbial community dissimilarities. Although host-symbiont interactions have been demonstrated in many insect groups, our knowledge of the prevalence and mechanisms of phylosymbiosis in insects is still limited. Here, we provide an order-by-order summary of the phylosymbiosis patterns in insects, including Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera. Then, we highlight the potential contributions of stochastic effects, evolutionary processes, and ecological filtering in shaping phylosymbiotic microbiota. Phylosymbiosis in insects can arise from a combination of stochastic and deterministic mechanisms, such as the dispersal limitations of microbes, codiversification between symbionts and hosts, and the filtering of phylogenetically conserved host traits (incl., host immune system, diet, and physiological characteristics).

Two new species of Sinolachnus Hille Ris Lambers (Hemiptera, Aphididae, Lachninae) from China.

Two new Sinolachnus species from China, Sinolachnusrubusis Qiao & Li, sp. nov. feeding on Rubus sp. from Shaanxi and Sichuan Provinces, and Sinolachnusyunnanensis Qiao & Li, sp. nov. feeding on Elaeagnus sp. from Yunnan Province, are described and illustrated. Keys to Sinolachnus species distributed in China are presented. All examined specimens are deposited in the National Zoological Museum of China, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.

Habitat fragmentation increases specialization of multi-trophic interactions by high species turnover.

Habitat fragmentation is altering species interactions worldwide. However, the mechanisms underlying the response of network specialization to habitat fragmentation remain unknown, especially for multi-trophic interactions. We here collected a large dataset consisting of 2670 observations of tri-trophic interactions among plants, sap-sucking aphids and honeydew-collecting ants on 18 forested islands in the Thousand Island Lake, China. For each island, we constructed an antagonistic plant-aphid and a mutualistic aphid-ant network, and tested how network specialization varied with island area and isolation. We found that both networks exhibited higher specialization on smaller islands, while only aphid-ant networks had increased specialization on more isolated islands. Variations in network specialization among islands was primarily driven by species turnover, which was interlinked across trophic levels as fragmentation increased the specialization of both antagonistic and mutualistic networks through bottom-up effects via plant and aphid communities. These findings reveal that species on small and isolated islands display higher specialization mainly due to effects of fragmentation on species turnover, with behavioural changes causing interaction rewiring playing only a minor role. Our study highlights the significance of adopting a multi-trophic perspective when exploring patterns and processes in structuring ecological networks in fragmented landscapes.

Cavariella Del Guercio (Hemiptera, Aphidinae, Macrosiphini) in China, with a new species, new synonymies, and first country records.

The genus Cavariella is distinguished from other Macrosiphini genera (Aphididae, Aphidinae) because it has a supra-caudal process on abdominal tergite VIII which possesses two setae distally. It is Holarctic in distribution, and half of its species are Asian. The Chinese fauna of this genus, 17 species, have been restudied, morphologically and through DNA barcodes. As a result: Cavariellahidaensis Takahashi is transferred to Elatobium; Cavariellasculptura Qiao & Xu, sp. nov. is described from specimens collected on Torilis and Cryptotaenia (Apiaceae); Cavariellacessana Zhang, Chen, Zhong & Li, syn. nov. and Cavariellalargispiracula Zhang, Chen, Zhong & Li, syn. nov. are respectively junior synonyms of Cavariellaaquatica (Gillette & Bragg) and Cavariellasapporoensis Takahashi; Cavariellagilgiana Zhang, Chen, Zhong & Li and Cavariellalhasana Zhang are confirmed as valid species and complete descriptions are provided; Cavariellabhutanensis Chakrabarti & Das, Cavariellanigra Basu, Cavariellapastinacae (Linnaeus), and Cavariellapustula Essig are recorded for the first time from China. Additionally, keys for species of Cavariella known in China are provided and modifications to the key by Blackman and Eastop of aphid species on Angelica (Aphids on World's Plants) are presented.

Revision of the genus Allocotaphis Börner, 1950 (Hemiptera, Homoptera, Aphididae, Macrosiphini).

Allocotaphis Börner, 1950 (Hemiptera, Homoptera, Aphididae, Aphidinae, Macrosiphini) and its three species are fully revised. The history of the descriptions of the involved taxa is critically presented. Descriptions of the known morphs of these species and complete information on the biology and distribution of the species are presented. Three subjective synonymies are established: Spinaphis L.K. Ghosh, 1986 syn. n. and Longisiphoniella Chakrabarti, Saha & Mandal, 1988 syn. n. of Allocotaphis Börner, 1950, and Longisiphoniella subterranea Chakrabarti, Saha & Mandal, 1988 syn. n. of Allocotaphis multisetosa (L.K. Ghosh, 1986) comb. n. An hypothesis for the formation of the genus and the speciation that took place within it is proposed.

Mother knows best: reproductive regulation of caste ratio in a social hemipteran.

This study presents a novel strategy for regulating caste ratio via maternal reproduction in a parthenogenetic social aphid, Pseudoregma bambucicola. Most mothers in the colony produce only soldiers or normal nymphs, whereas a small proportion of mothers can produce both castes. Changes in the expression of key genes, including those related to reproduction, fertility, and chemical communication, may be responsible for the differentiation in maternal reproduction and caste development.

The Oriental fungus-feeding genus Azaleothrips Ananthakrishnan, 1964 from China with one new species and four new records (Thysanoptera, Phlaeothripidae, Phlaeothripinae).

Azaleothrips, a genus of fungus-feeding Phlaeothripinae , is easily recognized by the complex sculpture on the body surface. It is species-rich in the Oriental region, with 10 species here recognized from China, including A.sphaericussp. nov. and four new records. An illustrated key to the species from China is provided.

The complete mitochondrial genome of Periphyllus diacerivorus Zhang, 1982 (Hemiptera: Aphididae: Chaitophorinae).

We assembled and annotated the complete mitochondrial genome of Periphyllus diacerivorus, which is the first complete mitogenome in subfamily Chaitophorinae. The circular mitogenome of P. diacerivorus is 16,148 bp long with an A + T content of 84.1%. It contains 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNAs (rRNAs), a large control region, and a special repeat region. All PCGs initiate with ATN and terminate with TAA or TAG except for cox1 and nad4, which are terminated with an incomplete stop codon T--. All tRNAs display the typical clover-leaf secondary structure except for trnS (AGN). The repeat region between trnE and trnF is 970 bp long, including 2.18 repeat units. In the phylogenetic analysis tree, P. diacerivorus clusters with Mindarus keteleerifoliae.

A new species of Eulachnus Del Guercio from China (Hemiptera: Aphididae: Lachninae).

We describe apterous and alate viviparous females of a new species of the Lachninae genus Eulachnus (Eulachnini) from China. The new species, Eulachnus blackmani sp. nov., can be easily separated from other Asian representatives of this genus: the ultimate rostral segments are without accessory setae; the spinal scleroites are larger than the pleural and marginal ones; there are a few very long setae on the distal part of the tibiae and on the hind tarsus. The new species is morphologically most similar to the European E. nigricola (Paek), and hence unusual within the Asian Eulachnus fauna.

A new species of Aphis (Aphidinae: Aphidini) feeding on Rubus from China.

A new species of the genus Aphis feeding on Rubus ellipticus in China, Aphis rogeri Qiao sp. nov. is described. The new species is distinguished by the presence in life of successive pleuro-marginal wax spots, rostrum reaching over meta-coxae and short siphunculi. The new species is supported by molecular data and morphological features. An updated key to Aphis species feeding on Rubus is provided.

Insights into the Evolution of Aphid Mitogenome Features from New Data and Comparative Analysis.

The complete mitochondrial genomes and their rearrangement patterns can provide useful information for inferring evolutionary history of organisms. Aphids are one of the insect groups with some unique mitogenome features. In this study, to examine whether some features in aphid mitogenomes are independent species-specific evolutionary events or clade-specific events at certain taxonomic levels, we sequenced three new aphid mitogenomes (Hormaphidinae: Ceratovacuna keduensis, Pseudoregma panicola; Lachninae: Nippolachnus piri) and compared them with all known aphid mitogenomes. The three mitogenomes are 16,059-17,033 bp in length, with a set of 37 typical mitochondrial genes, a non-coding control region and a tandem repeat region. The gene orders of them are all highly rearranged. Within the subfamily Hormaphidinae, the presence of repeat region and mitogenome rearrangement in Cerataphidini species but not in the other two tribes indicate that these may be Cerataphidini-specific features. The same gene rearrangement pattern in the two Lachninae species, N. piri (Tuberolachnini) and Stomaphis sinisalicis (Stomaphidini), supports that this feature should be at least derived from the common ancestor of two tribes. Overall, our data and analyses provide new insights into the evolutionary patterns of gene rearrangement and repeat region in aphid mitogenomes, and further corroborate the potential role of gene rearrangement in elucidating the evolutionary history of different insect lineages.

Chromosome-Level Genome Assembly of Callitettix versicolor (Rice Spittlebug).

The spittlebug family Cercopidae (Hemiptera: Auchenorrhyncha: Cicadomorpha: Cercopoidea) is distributed worldwide. Some Cercopidae species are agricultural pests that are responsible for substantial economic damage. However, the genomics of spittlebugs has rarely been studied and their complete genome assembly is yet to be reported. Here, we present the draft reference genome of Callitettix versicolor Fabricius (Hemiptera: Cercopidae) at the chromosome level. The assembled draft genome was 974.99 Mb with a contig N50 of 5.63 Mb, and the longest contig being 24.54 Mb. Hi-C technology was used to obtain an approximately 958.71 Mb chromosome-level genome on 10 pseudochromosomes, which covered 98.33% of the assembly. Repeat sequences accounted for 38.88% of the genomic sequences. A total of 21,937 protein-coding genes were detected in the reference genome, 89.97% of which were annotated in public databases. The high-quality reference genome of C. versicolor reported in this study will provide a valuable genomic resource for future ecological and evolutionary studies of spittlebugs.

The complete mitochondrial genome of Tuberolachnus salignus (Gmelin, 1790) (Hemiptera: Aphididae: Lachninae).

We sequenced the complete mitochondrial genome of Tuberolachnus salignus with a length of 16,868 bp, including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, a control region located between rrnS and trnI, and a repeat region located between trnS2 and trnF. All protein-coding genes are initiated with ATN and terminated with TAA, except the cox1, nad3 and nad4 with termination of T. The length of the repeat region is 1,407 bp, which repeats 4.04 times with a 305-bp unit. Our phylogenetic analysis showed T. salignus is sister to Stomaphis sinisalicis.

Insights Into the Species-Specific Microbiota of Greenideinae (Hemiptera: Aphididae) With Evidence of Phylosymbiosis.

Aphids and their symbionts represent an outstanding model for studies of insect-symbiont interactions. The aphid microbiota can be shaped by aphid species, geography and host plants. However, the relative importance of phylogenetic and ecological factors in shaping microbial community structures is not well understood. Using Illumina sequencing of the V3-V4 hypervariable region of the 16S rRNA gene, we characterized the microbial compositions of 215 aphid colonies representing 53 species of the aphid subfamily Greenideinae from different regions and plants in China, Nepal, and Vietnam. The primary endosymbiont Buchnera aphidicola and secondary symbiont Serratia symbiotica dominated the microbiota of Greenideinae. We simultaneously explored the relative contribution of host identity (i.e., aphid genus and aphid species), geography and host plant to the structures of bacterial, symbiont and secondary symbiont communities. Ordination analyses and statistical tests highlighted the strongest impact of aphid species on the microbial flora in Greenideinae. Furthermore, we found a phylosymbiosis pattern in natural Greenideinae populations, in which the aphid phylogeny was positively correlated with microbial community dissimilarities. These findings will advance our knowledge of host-associated microbiota assembly across both host phylogenetic and ecological contexts.

Phylosymbiotic Structures of the Microbiota in Mollitrichosiphum tenuicorpus (Hemiptera: Aphididae: Greenideinae).

Aphids harbor an array of symbionts that provide hosts with ecological benefits. Microbial community assembly generally varies with respect to aphid species, geography, and host plants. However, the influence of host genetics and ecological factors on shaping intraspecific microbial community structures has not been fully understood. In the present study, using Illumina sequencing of the V3 - V4 hypervariable region of the 16S rRNA gene, we characterized the microbial compositions associated with Mollitrichosiphum tenuicorpus from different regions and plants in China. The primary symbiont Buchnera aphidicola and the secondary symbiont Arsenophonus dominated the microbial flora in M. tenuicorpus. Ordination analyses and statistical tests suggested that geography and aphid genetics primarily contributed to the variation in the microbiota of M. tenuicorpus. We further confirmed the combined effect of aphid genetics and geography on shaping the structures of symbiont and secondary symbiont communities. Moreover, the significant correlation between aphid genetic divergence and symbiont community dissimilarity provides evidence for intraspecific phylosymbiosis in natural systems. Our study helped to elucidate the eco-evolutionary relationship between symbiont communities and aphids within one given species.