Contribution to the dragonfly (Insecta: Odonata) fauna of the Solomon Islands

The dragonfly fauna of the Solomon Islands remains incompletely documented, particularly across less-studied islands. This study presents the results of a field survey conducted in 2023 on Guadalcanal and Choiseul Island, based primarily on material collected during a multi-institutional expedition. A total of 40 species (and one undeterminded zygopteran species) were recorded, representing approximately 59% of the currently known dragonfly fauna of the Solomon Islands. Of these, five species (including Anax insulanus, Hemicordulia sp. nov. A, Hemicordulia sp. nov. B, and Solomonargiolestes sp. nov.) are newly recorded for Guadalcanal and the Solomon Archipelago, while Gynacantha mocsaryi is recorded for the first time for the the state Solomon Islands. 11 species are newly recorded for Choiseul Island. These results increase the total number of known dragonfly species in the Solomon Islands to 72 (excluding one undeterminded zygopteran species). The study also provides the first description of the female of Teinobasis chionopleura. The results confirm a high level of endemism in the region and refine species distributions, including the confirmation of Anax guttatus for the Solomon Islands and the exclusion of Anax gibbosulus from the regional fauna. Several taxonomic issues are highlighted, particularly within Agrionoptera, Lathrecista, and Rhyothemis, emphasising the need for further integrative studies. Ecological observations indicate strong associations of many species with shaded, fastflowing forest streams, as well as habitat-specific behavioural patterns. Sampling effort (16 effective fieldwork days) was influenced by logistical constraints, which should be considered when interpreting species richness and record numbers. The findings suggest that the current knowledge of Odonata diversity in the Solomon Islands remains incomplete and likely underestimated. Conservation recommendations are proposed, focusing on the preservation of riparian habitats, maintenance of aquatic habitat heterogeneity, and the promotion of citizen science initiatives such as iNaturalist.