Treehopper (Membracidae, Auchenorrhyncha) assemblages in four semi-arid areas of caatinga of Northeast Brazil

Abstract Treehopper assemblages were sampled in four semi-arid areas of caatinga in Northeast Brazil during the rainy seasons of 2016 and 2017, using three different capture methods. The areas are located in two Ecoregions of the Caatinga: “Depressão Sertaneja Setentrional” (Northern Sertaneja Depression) and “Planalto da Borborema” (Borborema Plateau). A total of 2,394 individuals of 43 species were sampled, corresponding to approximately 87% of the mean estimated species richness for all four areas. The species richness varied among the areas from 14 to 21, while the abundance of individuals ranged from 129 to 1860. Eighteen species were shared among areas, of which only Enchenopa eunicea, Sundarion sp. 1, Ceresa vitulus and Erosne parvula occurred in all four due to the general behavior of the first three and the wide distribution of host plant of Erosne parvula - Mimosa tenuiflora. Twenty-five species occurred only in one area, of which 23 were categorized as rare with a maximum of eight individuals sampled, and seven with only one individual collected (singletons). Considering that the Caatinga Domain possesses at least nine Ecoregions with different climates, geomorphology and vegetation, along with marked endemism of plants, it is expected that the species richness of treehoppers will increase substantially on a regional scale.

摘要：2016年与2017年雨季，研究人员采用三种不同采集方法，在巴西东北部卡廷加（Caatinga）的4个半干旱区域开展角蝉（Treehopper）类群采样。上述区域分属卡廷加的两个生态区："Depressão Sertaneja Setentrional"（北塞特兰赫亚洼地）与"Planalto da Borborema"（博尔博雷马高原）。本研究共采集到43种角蝉共计2394头个体，约占四个研究区域平均估计物种丰富度的87%。各区域的角蝉物种丰富度介于14至21之间，个体多度则在129至1860头范围内波动。共有18个跨区域分布的物种，其中仅Enchenopa eunicea、Sundarion sp.1、Ceresa vitulus以及Erosne parvula在全部四个区域均有分布，这源于前三种物种的广适性行为，以及Erosne parvula的寄主植物细叶含羞草（Mimosa tenuiflora）的广泛分布。另有25个物种仅在单个区域出现，其中23种被归类为稀有物种，其最大采样个体数仅为8头，另有7种仅采集到1头个体（单例种singletons）。鉴于卡廷加域（Caatinga Domain）至少存在9个气候、地貌与植被特征各异的生态区，且其植物类群具有显著的特有性，预计区域尺度上角蝉的物种丰富度将实现大幅提升。