Diversity and composition of island insects of the Bejaia region (Algeria)

The study was conducted on four islands located west of Bejaia (north?eastern Algeria) to collect baseline information about diversity and composition of insects. Data were collected during summer and spring of 2015 using traps, sweep nets and the Japanese umbrella sampling methods. A total of 1,691 individuals belonging to 112 species were collected. Totals of 72, 56, 41 and 34 species were recorded in Pisans Island, El Euch Island, Sahel Islet and Ail Islet, respectively. Of the 1,691 individuals recorded, 39.85?%, 30.51?%, 18.03?% and 11.59?% were recorded in Pisans Island, El Euch Island, Sahel islet and Ail islet, respectively. Shannon?weaver index ranged from 2.96 to 3.34 and Equitability between 0.77 and 0.87. The composition of the insect community differed between sampled islands (NMDS, Stress?=?0.013). Eleven (11) insect species composed over 50?% of dissimilarity between islands. Two species (Cassida viridis (L.) and Pheidole pallidula (Nyl.) accounted for more than 5?% of the diversity on all islands. Sorensen's similarity coefficient showed that Pisans and El Euch islands have the highest similarity (45.37?%), while the lowest similarity was recorded between Pisans Island and Sahel Islet (15.53?%).

本研究于阿尔及利亚东北部贝贾亚以西的四座岛屿开展，旨在获取昆虫多样性与群落组成的基线数据。2015年春夏两季，研究采用诱捕器、扫网及日式伞形采样法（Japanese umbrella sampling methods）完成数据采集工作。本次调查共采集到隶属于112个物种的1691个昆虫个体。其中，皮桑岛（Pisans Island）、埃尔乌奇岛（El Euch Island）、萨赫莱小岛（Sahel Islet）与艾尔小岛（Ail Islet）分别记录到72、56、41和34个昆虫物种；在所统计的1691个个体中，上述四座岛屿的个体占比分别为39.85%、30.51%、18.03%与11.59%。本研究的香农-威纳指数（Shannon-Weaver index）取值范围为2.96至3.34，均匀度指数（Equitability）介于0.77至0.87之间。不同采样岛屿间的昆虫群落组成存在显著差异（非度量多维尺度分析（NMDS），应力值=0.013）。共有11种昆虫物种贡献了岛屿间50%以上的群落相异度，其中绿龟甲（Cassida viridis (L.)）与淡足大头蚁（Pheidole pallidula (Nyl.)）这两个物种在所有岛屿的昆虫多样性中占比均超过5%。索伦森相似性系数（Sorensen's similarity coefficient）分析结果显示，皮桑岛与埃尔乌奇岛的群落相似性最高（45.37%），而最低相似性出现在皮桑岛与萨赫莱小岛之间（15.53%）。