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Arachnida is an exceptionally diverse class in the Arthropoda, consisting of 20 orders and playing crucial roles in the terrestrial ecosystems. However, their interordinal relationships have been debated for over a century. Rearranged or highly rearranged mitochondrial genomes (mitogenomes) were consistently found in this class, but their various extent in different lineages and efficiency for resolving arachnid phylogenies are unclear. Here, we reconstructed phylogenetic trees using mitogenome sequences of 290 arachnid species to decipher interordinal relationships as well as diversification through time. Our results recovered monophyly of ten orders (i.e. Amblypygi, Araneae, Ixodida, Mesostigmata, Opiliones, Pseudoscorpiones, Ricinulei, Sarcoptiformes, Scorpiones and Solifugae), while rejecting monophyly of the Trombidiformes due to the unstable position of the Eriophyoidea. The monophyly of Acari (subclass) was rejected, possibly due to the long-branch attraction of the Pseudoscorpiones. The monophyly of Arachnida was further rejected because the Xiphosura nested within arachnid orders with unstable positions. Mitogenomes that are highly rearranged in mites but less rearranged or conserved in the remaining lineages point to their exceptional diversification in mite orders; however, shared derived mitochondrial (mt) gene clusters were found within superfamilies rather than interorders, confusing phylogenetic signals in arachnid interordinal relationships. Molecular dating results show that arachnid orders have ancient origins, ranging from the Ordovician to the Carboniferous, yet have significantly diversified since the Cretaceous in orders Araneae, Mesostigmata, Sarcoptiformes, and Trombidiformes. By summarizing previously resolved key positions of some orders, we propose a plausible arachnid tree of life. Our results underline a more precise framework for interordinal phylogeny in the Arachnida and provide new insights into their ancient evolution.

The genus Calepitrimerus (Acari: Eriophyoidea) comprise more than 90 extant species. Most species infest angiosperms, while only five were reported from gymnosperms. Herein, we describe and illustrate three new species of the genus Calepitrimerus from China: two from angiosperms, C. huayanlingense sp. nov. on Ficus erecta (Moraceae), C. cryptocaryaer sp. nov. on Cryptocarya concinna (Lauraceae), and one from a gymnosperm, C. liuanense sp. nov. on Cryptomeria japonica (Cupressaceae). All new species were found vagrant on lower surfaces of their hosts’ leaves, albeit inducing no apparent symptom. A list of Calepitrimerus species in China is tabulated.

The superfamily Eriophyoidea includes5000 named species of very small phytophagous mites. As for many groups of phytophagous invertebrates, factors responsible for diversification of eriophyoid mites are unclear. Here, we used an inferred phylogeny of 566 putative species of eriophyoid mites based on fragments of two mitochondrial genes and two nuclear genes to examine factors associated with their massive evolutionary diversification through time. Our dated phylogeny indicates a Carboniferous origin for gymnosperm-associated Eriophyoidea with subsequent diversification involving multiple host shifts to angiosperms-first to dicots, and then to monocots or shifts back to gymnosperms-beginning in the Cretaceous period when angiosperms diverged. Speciation rates increased more rapidly in the Eriophyidae + Diptilomiopidae (mostly infesting angiosperms) than in the Phytoptidae (mostly infesting gymnosperms). Phylogenetic signal, speciation rates, dispersal and vicariance results combined with inferred topologies show that hosts played a key role in the evolution of eriophyoid mites. Speciation constrained by hosts was probably the main driver behind eriophyoid mite diversification worldwide. We demonstrate monophyly of the Eriophyoidea, whereas all three families, most subfamilies, tribes, and most genera are not monophyletic. Our time-calibrated tree provides a framework for further evolutionary studies of eriophyoid mites and their interactions with host plants as well as taxonomic revisions above the species level.

Eriophyoid mites (Eriophyoidea) are distributed worldwide and are the largest superfamily in the Acari. After over one and a half centuries of field surveys, regional fauna of eriophyoid mites remains unclear. The genus

Eriophyoid mites (Acari: Eriophyoidea) are among the smallest of terrestrial arthropods and the most species-rich group of herbivorous mites with a high host specificity. However, knowledge of their species diversity has been impeded by the difficulty of their morphological differentiation. This study assembles a DNA barcode reference library that includes 1850 mitochondrial COI sequences which provides coverage for 45% of the 930 species of eriophyoid mites known from China, and for 37 North American species. Sequence analysis showed a clear barcode gap in nearly all species, reflecting the fact that intraspecific divergences averaged 0.97% versus a mean of 18.51% for interspecific divergences (minimum nearest-neighbour distances) in taxa belonging to three families. Based on these results, we used DNA barcoding to explore the species diversity of eriophyoid mites as well as their host interactions. The 1850 sequences were assigned to 531 barcode index numbers (BINs). Analyses examining the correspondence between these BINs and species identifications based on morphology revealed that members of 45 species were assigned to two or more BINs, resulting in 1.16 times more BINs than morphospecies. Richness projections suggest that over 2345 BINs occurred at the sampled locations. Host plant analysis showed that 89% of these mites (BINs) attack only one or two congeneric host species, but the others have several hosts. Furthermore, host-mite network analyses demonstrate that eriophyoid mites are high host-specific, and modularity is high in plant-mite networks. By creating a highly effective identification system for eriophyoid mites in the Barcode of Life Data Systems database (BOLD), DNA barcoding will advance our understanding of the diversity of eriophyoid mites and their host interactions.

Two new species of eriophyoid mites from China are described and illustrated. They are Phyllocoptes broccolis sp. nov. on Mucuna macrocarpa (Leguminosae), and Apodiptacus hongkouianus sp. nov. on Bambusa sp. (Poaceae). Both new eriophyoid mite species are vagrants causing no apparent symptom to their host plants.

Local adaptation is particularly likely in invertebrate pests that typically have short generation times and large population sizes, but there are few studies on pest species investigating local adaptation and separating this process from contemporaneous and historical gene flow. Here, we use a population genomic approach to investigate evolutionary processes in the two most dominant spider mites in China, Tetranychus truncatus Ehara and Tetranychus pueraricola Ehara et Gotoh, which have wide distributions, short generation times, and large population sizes. We generated genome resequencing of 246 spider mites mostly from China, as well as Japan and Canada at a combined total depth of 3,133×. Based on demographic reconstruction, we found that both mite species likely originated from refugia in southwestern China and then spread to other regions, with the dominant T. truncatus spreading ~3,000 years later than T. pueraricola. Estimated changes in population sizes of the pests matched known periods of glaciation and reinforce the recent expansion of the dominant spider mites. T. truncatus showed a greater extent of local adaptation with more genes (76 vs. 17) associated with precipitation, including candidates involved in regulation of homeostasis of water and ions, signal transduction, and motor skills. In both species, many genes (135 in T. truncatus and 95 in T. pueraricola) also showed signatures of selection related to elevation, including G‐protein‐coupled receptors, cytochrome P450s, and ABC‐transporters. Our results point to historical expansion processes and climatic adaptation in these pests which could have contributed to their growing importance, particularly in the case of T. truncatus.

Privacy amplification (PA) is the art of distilling a highly secret key from a partially secure string by public discussion. It is a vital procedure in quantum key distribution (QKD) to produce a theoretically unconditional secure key. The throughput of PA has become a bottleneck of the high-speed discrete variable QKD (DV-QKD) system. In this paper, a high-speed modular arithmetic hash PA scheme with GNU multiple precision (GMP) arithmetic library is presented. This scheme is implemented on two different central processing unit (CPU) platforms. The experimental results demon-strate that the throughput of this scheme achieves 260Mbps on the block size of 10^6 and 140Mbps on the block size of 10^8. This is the highest-speed recorded PA scheme on CPU platform to the author's knowledge., 5 pages. 6 figures

The deck landing sinking velocity of carrier-based aircraft is affected by carrier attitude, sea condition, aircraft performance, etc. Its impact analysis is a complex nonlinear problem, and there even is some contradictory phenomenon that when the approach velocity increases, the sinking velocity decreases under certain circumstances. Aiming at exploring the impact of the various related deck landing parameters on sinking velocity for carrier-based aircraft in the actual environment, response surface method-based improved Kriging algorithm (IK-RSM) is proposed based on genetic algorithm and Kriging model. Based on the deck landing measured data of the F/A-18A aircraft in the actual operating environment, the impact degree of the 15 deck landing parameters on the sinking velocity is explored, respectively, by using the partial correlation analysis of multivariate statistical theory and the IK-RSM. It can be found that the 4 parameters are strongly correlated with the sinking velocity; that is, the aircraft glide angle and deck pitch angle are highly correlated with the sinking velocity; next, the approach velocity and the engaging velocity are moderately correlated with the sinking velocity. The 4 parameters above could be used to establish the impact analysis model of the sinking velocity. The genetic algorithm is applied to the correction coefficients optimization of the IK-RSM’s kernel functions, and the IK-RSM of the F/A-18A aircraft sinking velocity is formed. Compared with the Kriging model and the empirical formula, the sinking velocity prediction accuracy indexes of IK-RSM are the best; for example, the determination coefficient is 0.981, the mean relative error is 1.813%, and the maximum relative error is 6.771%. Furthermore, based on the sinking velocity IK-RSM and the sensitivity analysis method proposed, we have explained the reason for the contradictory phenomenon that when the approach velocity increases, the sinking velocity decreases at some samples. It could provide certain technical support for the flight attitude control related to the sinking velocity during the actual flight of carrier-based aircraft.

Five new eriophyoid mites infesting weeds of the family Poaceae are described and illustrated from Egypt. They are Abacarus stagninis sp. nov. from Echinochloa stagnina (Retz.) P. Beauv., vagrants in grooves between veins on the upper leaf surface, causing discoloration of the leaves; and four new species from genus Aceria (A. echinochloae sp. nov., A. barnyardi sp. nov., and A. stagninis sp. nov.) from E. stagnina and E. crus–galli (L.) Beauv., and Aceria pennisetosa sp. nov., from Pennisetum purpureum Schumach. These species are vagrants underneath inner surface of the leaf sheath around stem and no symptoms were observed. However, A. barnyardi sp. nov. is a vagrant underneath inner surface of the leaf sheath around stem and are endoparasitic inside tissue of leaves causing rusted leaves.

Three new species of the tribe Phyllocoptini (Acari: Eriophyidae) from China, are described and illustrated. They are Phyllocoptes gaotainensus sp. n. on Populus euphratica (Salicaceae), Calepitrimerus anomalus sp. n. on Paeonia anomala (Paeoniaceae) and Paraepitrimerus stellarus sp. n. on Stellaria sp. (Caryophyllaceae). Based on the characteristics of dorsal and ventral annuli smooth, P. gaotainensus sp. n. may represent a deutogyne form. All three new species are vagrant on the lower leaf surface. No damage to the host was observed.

The center–periphery hypothesis (CPH) states that the genetic diversity, genetic flow, and population abundance of a species are highest at the center of the species’ geographic distribution. However, most CPH studies have focused on the geographic distance and have ignored ecological and historical effects. Studies using niche models to define the center and periphery of a distribution and the interactions among geographical, ecological, and historical gradients have rarely been done in the framework of the CPH, especially in biogeographical studies of animal species. Here, we examined the CPH for a widely distributed arthropod, Tetranychus truncatus (Acari: Tetranychidae), in eastern China using three measurements: geographic distance to the center of the distribution (geography), ecological suitability based on current climate data (ecology), and historical climate data from the last glacial maximum (history). We found that the relative abundances of different populations were more strongly related to ecology than to geography and history. Genetic diversity within populations and genetic differentiation among populations based on mitochondrial marker were only significantly related to history. However, the genetic diversity and population differentiation based on microsatellites were significantly related to all three CPH measurements. Overall, population abundance and genetic pattern cannot be explained very well by geography alone. Our results show that ecological gradients explain the variation in population abundance better than geographic gradients and historical factors, and that current and historical factors strongly influence the spatial patterns of genetic variation. This study highlights the importance of examining more than just geography when assessing the CPH.

Eriophyoid mites (Acari: Eriophyoidea) comprise approximately 5000 named species, leading to the most species-rich superfamily in the Acari. They are strictly herbivorous with a high level of host specificity, reflecting 89% of these mites attack only one or two congeneric host species (Yin et al., 2022).

One new genus and six new species of eriophyoid mite from Mountain Trusmadi, Malaysia are described and illustrated. They are Isoannulus morrisianae sp. nov. on Diospyros morrisiana (Ebenaceae), Abacarus bicolorus sp. nov. on Lespedeza bicolor (Leguminosae), Parneometaculus persicariae gen. nov. & sp. nov. on Persicaria chinensis (Polygonaceae), Shevtchenkella miscanthis sp. nov. on Miscanthus floridulus (Poaceae), Davisella nitidis sp. nov. on Artocarpus nitidus subsp. lingnanensis (Moraceae), and Vimola blastis sp. nov. on Blastus cochinchinensis (Melastomataceae). Furthermore, two new records of eriophyoid mites are found: Knorella bambusae (Kuang & Feng, 1989) rec. nov. on Bambusa sp. (Poaceae) and Diptilomiopus melastomae (Boczek & Chandrapatya, 2002) rec. nov. on Melastoma malabathricum (Melastomataceae). All these new eriophyoid mite species and new records are vagrants causing no apparent symptom to their host plants.

The red tomato spider mite, Tetranychus evansi Baker & Pritchard, is a newly emerged and globally invasive pest of solanaceous plants. In this study, the complete mitochondrial genome of T. evansi was sequenced using Illumina Hiseq technology. The complete mitochondrial genome of T. evansi is a typical circular DNA with a length of 13,064 bp, which contains 37 genes arranged in consistent with the typical metazoan mitochondrial genomes. Highly truncated mitochondrial tRNAs were observed, with 18 of the 22 tRNAs appearing to lack the D- or T- arms or both. A preliminary phylogenic analysis showed that mitochondrial genome can significantly improve the reliability of phylogenetic inference relative to short sequences, as indicated by the elevated bootstrap values. This mitochondrial genome provides a valuable source for the future phylogenetic analyses and helps clear the introduction origins of the Chinese T. evansi populations.

Previous research showed that wind characteristics were influenced by terrain. To accurately calculate the wind-induced bridge response, this article presented a comprehensive investigation of the wind characteristics of a trumpet-shaped mountain pass by long-term monitoring. Basic strong wind characteristics such as the wind rose, turbulence intensities, turbulence length scales, turbulence spectra and normalized cross-spectrum were discussed using 10 min intervals. Due to the different types of terrain on the two sides of the bridge site, this article attempted to reflect the influence of the terrain on the wind characteristics in different wind directions. The scatter plots of wind characteristics were presented directly on the terrain map. The effects of the turbulence characteristics, mean wind speed and aerodynamic admittance function on buffeting response of the composite cable-stayed bridge were discussed by the multimode coupled frequency domain. The results show that the wind profile is extremely twisted. The larger turbulent integral scale and the lower turbulence intensity appear in the direction along the river. The effect of the mean wind speed on the buffeting response is greater than that of the fluctuating wind characteristics. The aerodynamic admittance function proposed by Holmes has the largest reduction in buffeting response.

One new genus and two new species of eriophyid mites (Acari: Eriophyidae) from China are described and illustrated. They are Grandiscapitis camelliae gen. nov. and sp. nov. on Camellia olei...

Nine new eriophyoid mite species of the genus Diptilomiopus (Acari: Diptilomiopidae) from China and Malaysia are described and illustrated. They are D. broussonetus sp. nov. on Broussonetia sp. (Moraceae), D. callicarpus sp. nov. on Callicarpa bodinieri (Lamiaceae), D. fortunus sp. nov. on Alniphyllum fortunei (Styracaceae), D. keningaus sp. nov. on Stephania sp. (Menispermaceae), D. milletus sp. nov. on Adinandra milletii (Pentaphylacaceae), D. nobilus sp. nov. on Sterculia nobilis (Malvaceae), D. octandrus sp. nov. on Aporosa octandra (Phyllanthaceae), D. rotundus sp. nov. on Ilex rotunda (Aquifoliaceae), and D. sabahus sp. nov. on Morus sp. (Moraceae). All new species are vagrant on lower leaf surface. No damage to the host was observed.

Oribatida s.l. represents one of the most species-rich mite lineages, including two recognized groups: oribatid mites (Oribatida s.s., non-astigmatan oribatids) and astigmatid mites (Astigmata). However, the relationship between these two groups has been debated. Here, we sequenced the complete mitochondrial (mt) genome of one oribatid mite and one astigmatid mite, retrieved complete mt genomes of three oribatid mites, and compared them with two other oribatid mites and 12 astigmatid mites sequenced previously. We find that gene orders in the mt genomes of both oribatid mites and astigmatid mites are rearranged relative to the hypothetical ancestral arrangement of the arthropods. Based on the shared derived gene clusters in each mt genome group, rearranged mt genomes are roughly divided into two groups corresponding to each mite group (oribatid mites or astigmatid mites). Phylogenetic results show that Astigmata nested in Oribatida. The monophyly of Astigmata is recovered, while paraphyly of Oribatida s.s. is observed. Our results show that rearranged gene orders in the mt genomes characterize various lineages of oribatid mites and astigmatid mites, and have potential phylogenetic information for resolving the high-level (cohort or supercohort) phylogeny of Oribatida.

Combining P-type iterative learning (IL) control, fuzzy logic control and artificial bee colony (ABC) algorithm, a new optimal fuzzy IL controller is designed for active vibration control of piezoelectric smart structures. In order to accelerate the learning speed of feedback gain, the fuzzy logic controller is integrated into the ANSYS finite element (FE) models by using APDL (ANSYS Parameter Design Language) approach to adjust adaptively the learning gain of P-type IL control. For improving the performance and robustness of the fuzzy logic controller as well as diminishing human intervention in the operation process, ABC algorithm is used to automatically identify the optimal configurations for values in fuzzy query table, fuzzification parameters and defuzzification parameters, and the main program of ABC algorithm is operated in MATLAB. The active vibration equations are driven from the FE equations for the dynamic response of a linear elastic piezoelectric smart structure. Considering the vibrations generated by various external disturbances, the optimal fuzzy IL controller is numerically investigated for a clamped piezoelectric smart plate. Results demonstrate that the proposed control approach makes the feedback gain has a fast learning speed and performs excellent in vibration suppression. This is demonstrated in the results by comparing the new control approach with the P-type IL control.

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Accurate species delimitation is essential for the study of biodiversity, but morphological approaches often provide a limited ability to connect different life stages, sexes or other phenotypic variants in eriophyoid mites because many species possess two phenotypically distinct forms: protogynes and deutogynes. In this study, we analysed the morphological variation in 26 populations of the eriophyoid mite, Epitrimerus sabinae Xue & Hong, 2005 s.l., from sites across its entire known distribution and revealed three morphotypes (LNS: large, normal palp seta d; MBS: medium, bifurcated palp seta d; SBS: small, bifurcated palp seta d) distinguished by body size and structure of dorsal pedipalp genual seta. Five lines of evidence (morphometrics, DNA-based species delimitation, phylogenetics, haplotype network, mitochondrial genome architecture) indicated that the MBS and SBS groups were very distinct from LNS (E. sabinae s.s.). In fact, the MBS and SBS morphotypes are properly placed in the genus Leipothrix with the MBS lineage representing the protogyne of L. juniperensis, sp. nov., whereas the SBS lineage is its deutogyne. By expanding the approaches used to link protogynes and deutogynes of eriophyoid mites, this study provides a way to accelerate the delineation of species boundaries in this important group of plant pests.

Two Gram-stain negative halophilic strains, designated as LM2T and LM4, were isolated from Lake LongmuCo on Tibetan Plateau. These two strains were aerobic, catalaseand oxidase-positive, nonmotile and rod-shaped organisms. Phylogenetic analysis based on 16S rRNA gene sequences indicated that LM2T and LM4 belong to the genus Roseovarius, with Roseovarius tolerans EL-172T (97.3% and 97.4% 16S rRNA gene sequence similarity, respectively) and Roseovarius azorensis SSW084T (95.5% and 95.6% 16S rRNA gene sequence similarity, respectively) as their closest neighbors. Q-10 was the sole respiratory quinone of these two strains. The major fatty acids were C18:1ω7c/C18:1ω6c, C16:0, C19:0 cyclo ω8c, and 11-methyl C18:1ω7c. The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phospholipid of unknown structure containing glucosamine, and unidentified aminolipid. The DNA G + C content was between 64.2 and 64.5 mol%. DNA-DNA hybridization showed 96.7% relatedness between LM2T and LM4, 24.9% relatedness between LM2T and R. tolerans EL-172T, and 36.3% relatedness between LM4 and R. tolerans EL-172T. Based on phylogenetic analysis, DNA-DNA hybridization, a range of physiological and biochemical characteristics, LM2T and LM4 belong to the same species and were clearly distinguished from the type strains of the genus Roseovarius. It was evident that LM2T and LM4 could be classified as a novel species of the genus Roseovarius, for which the name Roseovarius tibetensis sp. nov. is proposed. The type strain is LM2T (= CGMCC 1.16230T = KCTC 62028T).

Eriophyoid mites (superfamily Eriophyoidea) comprise >4400 species worldwide. Despite over a century of study, the phylogenetic position of these mites within Acariformes is still poorly resolved. Currently, Eriophyoidea is placed in the order Trombidiformes. We inferred the high-level phylogeny of Acari with the mitochondrial (mt) genome sequences of 110 species including four eriophyoid species, and the nuclear small subunit (18S) rRNA gene sequences of 226 species including 25 eriophyoid species. Maximum likelihood (ML), Bayesian inference (BI) and Maximum parsimony (MP) methods were used to analyze the sequence data. Divergence times were estimated for major lineages of Acari using Bayesian approaches. Our analyses consistently recovered the monophyly of Eriophyoidea but rejected the monophyly of Trombidiformes. The eriophyoid mites were grouped with the sarcoptiform mites, or were the sister group of sarcoptiform mites+non-eriophyoid trombidiform mites, depending on data partition strategies. Eriophyoid mites diverged from other mites in the Devonian (384Mya, 95% HPD, 352-410Mya). The origin of eriophyoid mites was dated to the Permian (262Mya, 95% HPD 230-307Mya), mostly prior to the radiation of gymnosperms (Triassic-Jurassic) and angiosperms (early Cretaceous). We propose that the placement of Eriophyoidea in the order Trombidiformes under the current classification system should be reviewed.

The Eriophyoidea, notable for specific morphological characters (four-legged mites) and gall-formation in host plants (gall mites), is one of the most species-rich superfamilies of Acari. Monophyly of the superfamily Eriophyoidea is accepted by all acarologists; however, monophyly of most genera has not been evaluated in a molecular phylogenetic network. Furthermore, most eriophyoid mites, especially species in the genus Diptilomiopus, are morphologically similar, challenging their identification. Here we test the phylogeny and cryptic diversity of Diptilomiopus species using fragments of two mitochondrial (COI and 12S) and two nuclear (18S and 28S) genes. Our results revealed the monophyly of Diptilomiopus. Sequence distance, barcode gap, and species delimitation analyses of the COI gene allowed us to resolve cryptic diversity of Diptilomiopus species. Additionally, we supposed that characteristics of genu fused with femur on both legs and seta ft′ absent on leg II evolved only once within Diptilomiopus, which are potential morphological synapomorphies. In contrast, characteristics of both setae ft′ and ft″ divided into a short branch and a long branch were supposed evolving multiple times independently. Our findings contribute to the understanding of phylogeny and morphological evolution of Diptilomiopus species and provide a DNA-based approach for species delimitation of Diptilomiopus mites.

While it has been proposed in several taxa that the mitochondrial genome is associated with adaptive evolution to different climatic conditions, making links between mitochondrial haplotypes and organismal phenotypes remains a challenge. Mitonuclear discordance occurs in the small brown planthopper (SBPH), Laodelphax striatellus, with one mitochondrial haplogroup (HGI) more common in the cold climate region of China relative to another form (HGII) despite strong nuclear gene flow, providing a promising model to investigate climatic adaptation of mitochondrial genomes. We hypothesized that cold adaptation through HGI may be involved, and considered mitogenome evolution, population genetic analyses, and bioassays to test this hypothesis. In contrast to our hypothesis, chill-coma recovery tests and population genetic tests of selection both pointed to HGII being involved in cold adaptation. Phylogenetic analyses revealed that HGII is nested within HGI, and has three nonsynonymous changes in ND2, ND5 and CYTB in comparison to HGI. These molecular changes likely increased mtDNA copy number, cold tolerance and fecundity of SBPH, particularly through a function-altering amino acid change involving M114T in ND2. Nuclear background also influenced fecundity and chill recovery (i.e., mitonuclear epistasis) and protein modelling indicates possible nuclear interactions for the two nonsynonymous changes in ND2 and CYTB. The high occurrence frequency of HGI in the cold climate region of China remains unexplained, but several possible reasons are discussed. Overall, our study points to a link between mtDNA variation and organismal-level evolution and suggests a possible role of mitonuclear interactions in maintaining mtDNA diversity.