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Global biodiversity gradients are generally expected to reflect greater species replacement closer to the equator. However, empirical validation of global biodiversity gradients largely relies on vertebrates, plants, and other less diverse taxa. Here we assess the temporal and spatial dynamics of global arthropod biodiversity dynamics using a beta-diversity framework. Sampling includes 129 sampling sites whereby malaise traps are deployed to monitor temporal changes in arthropod communities. Overall, we encountered more than 150,000 unique barcode index numbers (BINs) (i.e. species proxies). We assess between site differences in community diversity using beta-diversity and the partitioned components of species replacement and richness difference. Global total beta-diversity (dissimilarity) increases with decreasing latitude, greater spatial distance and greater temporal distance. Species replacement and richness difference patterns vary across biogeographic regions. Our findings support long-standing, general expectations of global biodiversity patterns. However, we also show that the underlying processes driving patterns may be regionally linked.

BACKGROUND: Ostrinia furnacalis (ACB) and Ostrinia nubilalis (ECB) are devastating pests of the agricultural crop maize worldwide. However, little is known about their potential distribution and niche shifts during their global invasion. Since long‐term selection to past climate variability has shaped their historical niche breadth, such niche shifts may provide an alternative basis for understanding their responses to present and future climate change. By integrating the niche unfilling, stability, and expansion situations into a single framework, our study quantifies the patterns of niche shift in the spatial distribution of these two pests during the different periods. RESULTS: Our results show that the overall suitable habitats of ACB and ECB in the future decrease but highly and extremely suitable habitat will become more widespread, suggesting these two insects may occur more frequently in specific regions. Compared with Southeast Asia and Australia, the ACB niche in China exhibited expansion rather than unfilling. For ECB, initial niches have a tendency to be retained in Eurasia despite there also being potential for expansion in North America. The niche equivalency and similarity test results further indicate that niche shifts were common for both ACB and ECB in different survival regions during their colonization of new habitat and their suitable habitat changes during the paleoclimate were associated with climatic changes. CONCLUSIONS: These findings improve our understanding of the ecological characteristics of ACB and ECB worldwide, and will be useful in the development of prevention and control strategies for two insect pests worldwide. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Integrative taxonomic study of three species of the genus Tylostega revealed that the genetic distances of the COI gene among the tested species was relatively large (3.27-7.60%). The Automatic Barcode Gap Discovery (ABGD) system performed better than the Barcode Index Number (BIN) in discriminating closely related species. This work provides a molecular baseline for future integrative taxonomic study of Crambidae. [ABSTRACT FROM AUTHOR]

We investigated the effectiveness of the standard 648 bp mitochondrial COI barcode region in discriminating among Satyrine species from China. A total of 214 COI sequences were obtained from 90 species, including 34 species that have never been barcoded. Analyses of genetic divergence show that the mean interspecific genetic divergence is about 16-fold higher than within species, and little overlap occurs between them. Neighbour-joining (NJ) analyses showed that 48 of the 50 species with two or more individuals, including two cases with deep intraspecific divergence (>3%), are monophyletic. Furthermore, when our sequences are combined with the conspecific sequences sampled from distantly geographic regions, the “barcoding gap” still exists, and all related species are recovered to be monophyletic in NJ analysis. Our study demonstrates that COI barcoding is effective in discriminating among the satyrine species of China, and provides a reference library for their future molecular identification. [ABSTRACT FROM AUTHOR]