Abundance and Seasonal Migration Patterns of Green Lacewings (Neuroptera: Chrysopidae) across the Bohai Strait in Eastern Asia

Many insects, including green lacewings, migrate seasonally to exploit suitable breeding and winter habitats. Green lacewings are important natural enemies of insect pests worldwide. Here, four dominant green lacewing species, Chrysoperla nipponensis (Okamoto), Chrysopa pallens (Rambur), Chrysoperla furcifera (Okamoto), and Chrysopa formosa Brauer, were investigated for their ability to migrate between northern and northeastern China across the Bohai Strait from late May to late October each year. Furthermore, there were significant interannual and seasonal differences in the number of migratory green lacewings collected. The number of green lacewings in spring was significantly lower than that in summer and autumn, and the highest average number of green lacewings occurred in June. In addition, there were differences in the sex ratio of migrating green lacewings between months, with a greater proportion of females than males. Finally, the seasonal migration trajectories simulated by the HYSPLIT model revealed that the green lacewings captured on Beihuang Island primarily originated from Shandong Province. Accordingly, these findings contribute to our understanding of green lacewing migration in eastern Asia and aid its incorporation within integrated pest management (IPM) packages for several crop pests. Furthermore, long-term tracking of migrant insect populations can reveal ecosystem services and trophic dynamic processes at the macroscale.

Comprehensive DNA barcode reference library and optimization of genetic divergence threshold facilitate the exploration of species diversity of green lacewings (Neuroptera: Chrysopidae)

Chrysopidae are a family of Neuroptera of significant importance in biocontrol against agricultural pests because of their predatory larvae. Currently, the taxonomy of Chrysopidae lacks a comprehensive revision, which impedes the exploration of species diversity as well as the selection and the conservation of green lacewings as biocontrol agents. We have established a DNA barcode reference library of the Chinese green lacewings based on an approximately complete sampling (95.63%) in 25 of the 34 provincial regions in China, comprising 1 119 barcodes of 25 genera and 197 species (representing 85% genera and 43.62% species from China). Combining other 1 049 high quality green lacewing DNA barcodes, we first inferred the optimal threshold of interspecific genetic divergence (1.87%) for successful species identification in multiple simulated scenarios based on present data. We further inferred the threshold of genetic divergence (7.77%) among genera with biocontrol significance. The inference and performance of the threshold appears to be mainly associated with the completeness of sampling, the proportion of closely related species, and the analytical approaches. Six new combinations, Apertochrysa platypa (Yang & Yang, 1991) comb. nov., Apertochrysa shennongana (Yang & Wang, 1990) comb. nov., Apertochrysa pictifacialis (Yang, 1988) comb. nov., Apertochrysa helana (Yang, 1993) comb. nov., Plesiochrysa rosulata (Yang & Yang, 2002) comb. nov., and Signochrysa hainana (Yang & Yang, 1991), are proposed according to integrative species delimitation. Our library and optimal threshold will effectively facilitate the exploration of species diversity of green lacewings. Our study also provides a methodological reference in molecular delimitation of other insects.

Stability and Assembly Mechanisms of Butterfly Communities across Environmental Gradients of a Subtropical Mountain

Mountain ecosystems harbor evolutionarily unique and exceptionally rich biodiversity, particularly in insects. In this study, we characterized the diversity, community stability, and assembly mechanisms of butterflies on a subtropical mountain in the Chebaling National Nature Reserve, Guangdong Province, China, using grid-based monitoring across the entire region for two years. The results showed that species richness, abundance, and Faith's phylogenetic diversity decreased with increasing elevation; taxonomic diversity played a considerable role in mediating the effects of environmental changes on stability. Moreover, our results showed that stochastic processes are dominant in governing the assembly of butterfly communities across all elevational gradients, with habitats at an elevation of 416-580 m subjected to the strongest stochastic processes, whereas heterogeneous selection processes displayed stronger effects on the assembly of butterfly communities at 744-908 m, 580-744 m, and 908-1072 m, with abiotic factors inferred as the main driving forces. In addition, significant differences were detected between the barcode tree and the placement tree for the calculated β-NTI values at 416-580 m. Overall, this study provides new insights into the effects of environmental change on the stability and assembly of butterflies in Chebaling, which will be beneficial for biodiversity conservation and policy development.

A new species of Apertochrysa Tjeder, 1966 and new record of Plesiochrysa ramburi (Schneider, 1851) (Neuroptera: Chrysopidae) from China, with potential biocontrol significance

A new green lacewing species Apertochrysa roseusfrontata sp. nov. and a newly recorded Plesiochrysa ramburi (Schneider, 1851) (Neuroptera: Chrysopidae: Chrysopinae) from South China are described based on the morphological characters of both adults and larvae. Both species were found predating Dysmicoccus neobrevipes Beardsley, 1959 (Hemiptera: Pseudococcidae) on sisal (Agave sisalana Perrine, 1838) in Guangdong Province.

Macrofungal Diversity and Distribution Patterns in the Primary Forests of the Shaluli Mountains

The Shaluli Mountains are located in the southeastern part of the Tibetan Plateau at an elevation of 2500-5000 m. They are characterized by a typical vertical distribution of climate and vegetation and are considered a global biodiversity hotspot. We selected ten vegetation types at different elevation gradients representing distinct forests in the Shaluli Mountains to assess the macrofungal diversity, including subalpine shrub, Pinus spp., Populus spp., Pinus spp. and Quercus spp., Quercus spp., Abies spp., Picea spp. and Abies spp., Picea spp., Juniperus spp., and alpine meadow. In total, 1654 macrofungal specimens were collected. All specimens were distinguished by morphology and DNA barcoding, resulting in the identification of 766 species belonging to 177 genera in two phyla, eight classes, 22 orders, and 72 families. Macrofungal species composition varied widely among vegetation types, but ectomycorrhizal fungi were predominant. In this study, the analysis of observed species richness, the Chao1 diversity index, the invsimpson diversity index, and the Shannon diversity index revealed that the vegetation types with higher macrofungal alpha diversity in the Shaluli Mountains were composed of Abies, Picea, and Quercus. The vegetation types with lower macrofungal alpha diversity were subalpine shrub, Pinus spp., Juniperus spp., and alpine meadow. The results of curve-fitting regression analysis showed that macrofungal diversity in the Shaluli Mountains was closely related to elevation, with a trend of increasing and then decreasing with rising elevation. This distribution of diversity is consistent with the hump-shaped pattern. Constrained principal coordinate analysis based on Bray-Curtis distances indicated that macrofungal community composition was similar among vegetation types at similar elevations, while vegetation types with large differences in elevation differed significantly in macrofungal community composition. This suggests that large changes in elevation increase macrofungal community turnover. This study is the first investigation of the distribution pattern of macrofungal diversity under different vegetation types in high-altitude areas, providing a scientific basis for the conservation of macrofungal resources.

Distribution of Breeding Population and Predicting Future Habitat under Climate Change of Black-Necked Crane (Grus nigricollis Przevalski, 1876) in Shaluli Mountains

Climate change is affecting biodiversity by altering the geographical distribution range of species, and this effect is amplified in climate-sensitive areas. Studying the geographic distribution of flagship species in response to climate change is important for the long-term conservation of species and the maintenance of regional biodiversity. Therefore, we collected field survey records from 2016 to 2020 and conducted field surveys of black-necked cranes in the Shaluli Mountains (SLLMs) in May–June and August–October 2021; 103 breeding records were acquired totally, and the geographical distribution range under the current and four future climate scenarios was modeled with the MaxEnt model to predict the impact of climate change on its distribution and habitat quality. The results showed that 152 black-necked cranes were surveyed in seven counties of SLLMs in total; the estimated number of black-necked cranes in the entire SLLMs was about 200. The currently suitable habitat area is 27,122 km2, mainly distributed in gentle meadows and wetland habitats along the lake where the Annual Mean Temperature is −1 °C and the Mean Diurnal Range (16 °C) and Precipitation Seasonality (105) are comparatively large. Furthermore, the breeding range would expand to varying degrees under future climate scenarios and showed a migration trend toward the northwest and higher elevation. Besides, as time goes by, the habitat for black-necked cranes in SLLMs would become more homogeneous and more suitable. The conservation effectiveness of the existing reserve network would keep stable with climate change, although there are large conservation gaps between protected areas, and these gaps will gradually expand over time. Overall, this study provides a preliminary understanding of the population and distribution and predicts the future distribution of black-necked cranes in the SLLMs. It also demonstrates the importance of SLLMs for protecting the central population of black-necked cranes and maintaining regional biodiversity. Therefore, we recommend long-term monitoring and conservation of the black-necked crane population and wetland resources in the region.

Diversity of Lacewings (Neuroptera) in an Altitudinal Gradient of the Tacaná Volcano, Southern Mexico

Neuroptera is an order of insects with a moderate diversity of species numbers yet a high between-family morphological diversity, which has a significant ecological role as a predator. However, there are few studies focused on describing changes in species diversity along environmental gradients. We evaluated changes in the alpha and beta diversity of species and the higher taxa in Neuroptera communities in the Tacaná Volcano in southern Mexico. Five sites each at different altitudes were studied through systematic annual sampling. The taxonomic and phylogenetic alpha diversity were analyzed, as well as the beta diversity and its components, species turnover and nestedness. The alpha diversity had two trends: (1) decreased standardized richness and taxonomic distinctness with increasing altitude, and (2) increased estimated richness and species diversity at intermediate altitudes. The highest turnover values for species, as well as for supra-specific taxa, were recorded at sites with lower altitudes. The highest total beta diversity value was recorded at elevations above 3000 m, whereas the highest number of species and supra-specific taxa were observed at sites between 600 and 2000 m, with an evident decrease above 3000 m. The type of vegetation and environmental conditions may be influencing the decrease in diversity toward higher elevations, which could explain the niche specialization of Neuroptera species to particular sites within the gradient. These results highlight the need to study the environmental factors and their effects on species composition along an elevation gradient.

Effects of Soil Physico-Chemical Properties on Plant Species Diversity Along an Elevation Gradient Over Alpine Grassland on the Qinghai-Tibetan Plateau, China

Elevation gradient can reflect the effects of soil physico-chemical properties on plant species diversity. Alpine grassland on the QTP has suffered from a serious decline in plant species diversity. In this study, we investigated 112 sites recording plant community characteristics and collecting soil samples along an elevation gradient (3,500-5,200 m asl) in alpine meadow on the QTP. We analyzed the effects of soil physico-chemical properties on plant species composition and diversity by canonical ordination and spatial regression along an elevation gradient. The results showed that species richness of the overall plant communities decreased with the increasing elevation, and the Simpson dissimilarity index (β sim ) had a maximum at low elevation (3,500-4,000 m) with the value of 0.37. Soil available nitrogen content was the primary soil parameter affecting plant species composition and diversity in alpine grassland. The effect of soil available nitrogen content on plant species richness varied at different elevations. For Gramineae plants (G), plant species richness declined with the increase in soil available nitrogen content at low elevation (3,500-4,000 m), but rose at middle elevation (4,000-4,500 m). Soil available nitrogen content had a more significant limiting effect on species richness at high elevation (>4,500 m). These findings increase our understanding about the drivers of plant species diversity changes in alpine grassland on the QTP, and will provide insights into grassland restoration and sustainable management.