Phylogeny and classification of Nesobasis Selys, 1891 and Vanuatubasis Ober & Staniczek, 2009 (Odonata: Coenagrionidae)

<p>Island archipelagos in the South Pacific have relatively high species endemism within the insect order Odonata, specifically damselflies. <em>Nesobasis</em> Selys, 1891, an endemic damselfly genus from Fiji, includes over 20 species, but a clear understanding of its evolutionary relationship to other damselflies in the region is lacking. Scientists have questioned the monophyly of <em>Nesobasis</em> due to variations within the genus leading to the establishment of three divisions provisionally named as: <em>comosa-, erythrops- </em>and <em>longistyla- </em>groups. However, <em>Nesobasis</em> has shown to be monophyletic in previous phylogenetic analyses. Using additional species in this study, we investigate the phylogenetic relationships between <em>Nesobasis </em>and other damselflies from the region, specifically the endemic <em>Vanuatubasis</em> Ober & Staniczek, 2009 from the neighboring island archipelagos of Vanuatu. The relationship between these taxa has not yet been examined with molecular data. Five genes were used in a maximum likelihood phylogenetic reconstruction and examined morphological data to determine the relationship between these genera. Our results recover three distinct clades overall with <em>Vanuatubasis</em> nested within <em>Nesobasis</em> (i.e., non-monophyletic). <em>Vanuatubasis </em>is sister to the <em>longistyla</em> and <em>erythrops</em> groups. The third group, <em>comosa, </em>was found sister to the clade of <em>Vanuatubasis</em> (<em>longistyla </em>+ <em>erythrops</em>). As a result of these findings, we propose the new genus, <em>Nikoulabasis</em> gen. nov.</p>