The nominate subgenus of the mylabrine genus Mylabris is revised: five new species, M. (M.) alpicola sp.n., M. (M.) cernyi sp.n., M. (M.) mediorientalis sp.n., and M. (M.) pseudoemiliae sp.n., are described and figured; M. (M.) apiceguttata sp.n., is provisionally refered to the nominate subgenus. M. (M.) rishwani Makhan, 2012 is synonymized with M. (M.) quadripunctata (Linnaeus, 1767). The other 20 species are characterized by short descriptions and figures, and a key to the species is provided. Tentatively, M. barezensis and M. batnensis are placed in the nominate subgenus. The bionomics of the species is summarized in tables including information on phenology, elevation, habitat preference, host plants, larval biology, and host insects. Zoogeographic analysis of the subgenus was carried out on the basis of all available faunistic records from literature and collections which are summarized in Appendix.
Traditional methods for hydrochemical analyses are effective but less diversified, and are constrained to limited objects and conditions. Given their poor accuracy and reliability, they are often used in complement or combined with other methods to solve practical problems. Cluster analysis is a multivariate statistical technique that extracts useful information from complex data. It provides new ideas and approaches to hydrogeochemical analysis, especially for groundwater hydrochemical classification. Hierarchical cluster analysis is the most widely used method in cluster analysis. This study compared the advantages and disadvantages of six hierarchical cluster analysis methods and analyzed their objects, conditions, and scope of application. The six methods are: The single linkage, complete linkage, median linkage, centroid linkage, average linkage (including between-group linkage and within-group linkage), and Ward’s minimum-variance. Results showed that single linkage and complete linkage are unsuitable for complex practical conditions. Median and centroid linkages likely cause reversals in dendrograms. Average linkage is generally suitable for classification tasks with multiple samples and big data. However, Ward’s minimum-variance achieved better results for fewer samples and variables.
Mylabris is a diverse genus of Meloidae and includes over 170 species throughout the Palaearctic region, classified into 14 subgenera. The current classification is largely built on taxonomic works pre‐dating the application of cladistic methods and based on a few morphological characters. In the present study, we use molecular data from mitochondrial and nuclear loci sampled across Mylabrini to assess the monophyly of Mylabris and its subgenera, and to identify which diagnostic morphological characters used for taxa delimitation represent synapomorphic features. We obtain a robust phylogeny which is consistent across datasets (3‐, 4‐ and 5‐gene datasets), methods (Bayesian vs. Maximum Parsimony), and approaches (species tree vs. total evidence). The genus Mylabris is monophyletic provided that Pseudabris is included and Ammabris is excluded. Most of the morphology‐based subgenera are recovered as well‐supported phylogenetic clades. Although previous classifications based on number and shape of antennomeres were confounded by convergent evolution of these traits, mesosternal and male genitalia features provided unambiguous apomorphies of Mylabrini genera and subgenera. We integrate these insights into an updated phylogenetic systematics of Mylabris and Mylabrini blister beetles, and we provide the description of two new subgenera, Dvorabris and Pardabris.
While the individual effects of permafrost and seasonal frost on the interactions between groundwater and surface water have received much attention, few attempts have been made to investigate the effects of permafrost and seasonal frost together on groundwater flow and its interactions with surface water. In this study, hydraulic, chemical, and isotopic data as well as a Bayesian mixing model were employed to investigate the interactions between streams and groundwater, the contributions of groundwater to the mainstream, and their relationships to the distribution of permafrost and seasonal frost in a representative subcatchment in the headwater region of the Heihe River Basin on the northeastern Qinghai‐Tibet Plateau in China. Our results showed that due to the freezing and thawing of recharge water sources and soils, the groundwater flow and stream flux from the permafrost zone to the seasonal frost zone increased during the thawing period, with maximum values in thawed period, and decreased during the frozen period. These variations affected groundwater recharge in the seasonal frost zone, resulting in dynamic changes in the groundwater table and the hydraulic gradient between the recharge and discharge points in the seasonal frost zone during the different freeze‐thaw periods. Correspondingly, the contribution of groundwater to the mainstream discharge decreased from 95% during the frozen period to 80%–90% during the thawing period. It then decreased to ∼40%–60% of the mainstream discharge during the thawed period and increased to ∼70%–90% during the refreezing period. From the permafrost zone to the seasonal frost zone and the catchment outlet, the aquifers in the piedmont plain of the seasonal frost zone play an important role in maintaining streamflows by switching their hydrological functions, that is, slowly releasing groundwater to maintain the streamflow during the frozen period and rapidly transferring the groundwater to mainstream during the thawed period.
Understanding factors influencing groundwater quality is critical to the development of best management practices at the large watershed scale. In this study, the shallow groundwater (10–20 m depth) in the Su-Xi-Chang region, eastern China, was investigated as part of a monitoring program from 2007 to 2008 to analyze the regional groundwater quality as well as the hydrogeochemical processes and their controlling factors. Conventional physicochemical water parameters (pH, turbidity, electrical conductivity, dissolved oxygen, total phosphorus), major cations (Na+, Ca2+, Mg2+ and NH4+) and anions (Cl−, NO3− and SO42−) were measured. Hydrochemical methods and multivariate statistical methods were applied to analyze the hydrogeochemical signatures, origins, the similarities among the variables and to identify the main pollution sources in the groundwater. The results showed that (1) the concentrations of TDS (224.89–1086.70 mg/L) and turbidity (0.1–18.60 NTU) were higher than the class II groundwater quality standards in China and the WHO drinking water standards, (2) there were extremely high concentrations of ammonia (0.01–32.90 mg/L), with a mean value of 0.72 mg/L and (3) the nitrate concentrations (average value of 22.07 mg/L) exceeded the class III groundwater quality standards. The study also provided evidence that weathering, dissolution of carbonate, halite and silicate and cation exchange were the possible primary hydrogeochemical control mechanisms in the groundwater. The sources of ammonia, total phosphorus, sulfates and nitrates included rock–water interactions and anthropogenic activities. The groundwater administration of pollution sinks and sources, long-term legal frameworks and economic incentives should be improved to optimize watershed scale management in the context of rapid development in China.
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