Centers of endemism and diversity patterns for typhlocybine leafhoppers (Hemiptera: Cicadellidae: Typhlocybinae) in China

Abstract

This study identifies 'centers of endemism' for typhlocybine leafhoppers in China, revealing diversity patterns and congruence of patterns between total species richness and endemism. Distribution patterns of 774 Typhlocybinae (607 described and 167 undescribed species) were mapped on a 1.5° × 1.5° latitude/longitude grid. Total species richness, endemic species richness and weighted endemism richness were calculated for each grid cell. Grid cells within the top 5% highest values of weighted endemism richness were considered as 'centers of endemism'. Diversity patterns by latitude and altitude were obtained through calculating the gradient richness. A congruence of diversity patterns between total species richness and endemism was confirmed using correlation analysis. To investigate the bioclimatic factors (19 variables) contributing to the congruence between total species richness and endemism, we compared the factor's difference between non-endemic and endemic species using the Kruskal-Wallis test. Eleven centers of endemism, roughly delineated by mountain ranges, were identified in central and southern China, including the south Yunnan, Hengduan Mountains, Qinling Mountains, Hainan Island, Taiwan Island and six mountain areas located in western Sichuan, northwest Fujian, southeast Guizhou, southeast Hunan, central and western Guangdong, and north Zhejiang. Total species richness and endemic species richness decreased with increased latitude and had a consistent unimodal response to altitude. The proportions of endemism decreased with increased latitude and increased with rising altitude. Diversity patterns between total species richness and endemism were highly consistent, and 'Precipitation of Coldest Period' and 'Temperature of Coldest Period' may contribute to the congruence of pattern. Migration ability may play a role in the relationship of endemism and species richness; climate, environment factors and important geologic isolation events can also play crucial effects on relationships under special conditions.

Determinants of Delphacidae richness and endemism in China

“…The centres of species richness and endemism reported here are consistent with the reports of other insects, including aphids (Liu et al ., 2009), scale insects (Wei et al ., 2016), grasshoppers (Xu, 2005), and leafhoppers (Yuan et al ., 2013). The diverse climate, long‐term stability of the environment, and complex geological history are regarded as the primary determinants of these insect richness centres (Yuan et al ., 2013; Wang et al ., 2017). These richness centres also have abundant delphacid host plants, such as Polygonaceae and bamboo (Zhao & Hou, 2011; Liu et al ., 2018), which act as a food source to generate and maintain high species richness and endemism.…”

“…In the Western Palearctic – areas highly affected by past glaciation and current climate change – researchers have determined how historical climatic factors (expressed per elevation range) have affected the patterns of insect richness and endemism (Schuldt & Assmann, 2009, 2011; Hortal et al ., 2011; Pinkert et al ., 2018). In China, where the climate has been relatively stable for a long time, most studies have analysed insect species richness patterns under current environmental conditions (Yuan et al ., 2013; Shen et al ., 2016; Wei et al ., 2016). Historical climate variables were included for the first time in a recent study on insect richness (Lyu et al ., 2020).…”

Distribution, congruence and hotspots of higher plants in China

“…We used grid-processed maps to analyze species diversity, hotspots, and spatial congruence, and then used generalized linear mixed models (GLMM) to analyze the spatial correlation of diversity information on the three different aspects. In analysis of the congruence, we defined the richest 5% biodiversity area as hotspots (hereafter referred to as “5%-based hotspots”) 50 . We then identified SR, ER, and TR hotspots, respectively and analyzed the spatial distribution congruence between each pair.…”

Spatial Patterns and Determinants of the Diversity of Hemipteran Insects in the Qinghai-Tibetan Plateau

“…Species categories and distribution records of Hemipteran insects were compiled primarily from the below resources: (1) Fauna Sinica published before this study (including aphids, plant bugs, scale insects, treehopper, flower bug, plant hopper and damsel bug); (2) the catalog of insect type specimens of China which indexed all insect type specimens from 1950 to 2010 (Cui et al, 2007(Cui et al, , 2009Bai et al, 2014); (3) the Global Biodiversity Information Facility (GBIF, http://www.gbif. org/); (4) literature survey for new Hemipteran species during 2000-2017 based on the Zoological Records; (5) supplementary raw data from published literature (e.g., Huang et al, 2006;Liu et al, 2009;Yuan et al, 2014;Wei et al, 2016); (6) the academic dissertations on Hemiptera groups searched by using the China Knowledge Resource Integrated Database; (7) specimen collection records from the Insect Systematics and Diversity lab at Fujian Agriculture and Forestry University.…”