A review of the damselfly fauna of the Austral Islands, French Polynesia, with descriptions of two new species (Odonata: Zygoptera: Coenagrionidae) Ronald A. Englund & Dan A. Polhemus The Zygoptera biota of the Austral Islands in French Polynesia is reviewed, and two new endemic species are described: Ischnura rurutana endemic to the island of Rurutu, and Ischnura jeanyvesmeyeri endemic to the island of Raivavae. Additional notes on coloration and ecological preferences are also given for Ischnura thelmae Lieftinck, 1966, endemic to Rapa, and the occurrence of the widespread species Ischnura aurora Brauer, 1865 on all the high islands in the Australs is briefly noted. Color photographs of adult males are provided for all three endemic Austral Island species, as well as figures of the male wing venation, pterothoracic color patterns, and male secondary genitalia, and the female dorsal pterothorax and lateral terminal abdomen. Scanning electron micrographs of the male abdominal appendages in various views are provided for all three endemic Austral Island Zygoptera species. Photographs are also provided for the breeding habitat and immature stage of I. rurutana. Dr. R.A. Englund*, J. Linsley Gressit Center for Entomological Research, Bishop Museum, 1525 Bernice Street, Honolulu, Hawaii 96817, USA. [email protected] Dr. D. A. Polhemus, Bishop Museum, 1525 Bernice Street, Honolulu, Hawaii 96817, USA. [email protected] Introduction and both the islands themselves and their aquatic The Zygoptera biota of the archipelagos contained habitats are generally difficult to access. Rapa, for within the modern political province of French example, has no airstrip, and only six or seven ships Polynesia is incompletely surveyed. Although only reach its shores in any given year. These islands have a few named species are recorded from this region, therefore been largely overlooked in terms of fresh- many new taxa are known to us from the Society, water entomological surveys. Marquesas, and Austral islands, based on recent sur- Recent work has now revealed that endemic dam- veys by the authors and colleagues. In this paper, we selfly species occur on three of the high Austral report on two new endemic species from the islands islands: Rurutu, Raivavae, and Rapa. Of the remain- of Rurutu and Raivavae in the Austral chain, and ing high islands in the group, Rimatara is small, review the Zygoptera fauna of the Austral Archipel- relatively low, has few streams, and is now heavily ago as a whole. disturbed by human occupation; surveys here have The Austral Islands are a hotspot chain lying in the revealed no Zygoptera other than the widespread South Pacific Ocean approximately 500 km south of Ischnura aurora Brauer, 1865. The other high Aus- Tahiti, and extending for approximately 1500 km tral island, Tubuai, is the largest in the group, rises in an ESE–WNW direction (Fig. 1). The islands to 422 m, and possesses rocky upland streams suit- composing the Australs are all relatively small, able for endemic damselflies. Surveys to date have Tijdschrift voor Entomologie 153: 25–40, Figs 1–34. [ISSN 0040–7496]. http://www.nev.nl/tve © 2010 Nederlandse Entomologische Vereniging. Published 1 June 2010. * Corresponding author 26 Tijdschrift voor Entomologie, volume 153, 2010 o o o 155 W 150 W 145 W o Fig. 1. Map of the Austral 20 S Islands, showing locations of islands discussed in text, and position of the Austal Maria Islands in relation to the Rurutu Rimatara Pacific Ocean as a whole. Tubuai Raivavae 25o S Rapa MAP AREA Marotiri 0 500 km not produced any endemic Zygoptera on this island, tron microscope housed at the National Museum of but we consider it possible that such species may Natural History in Washington, DC. exist, given that Tubuai is now known to harbor an Holotypes and paratypes are deposited either in the endemic genus of aquatic Heteroptera, Tubuaivelia National Museum of Natural History, Washing- (Polhemus & Polhemus 2008). ton, D.C. (USNM) or Bishop Museum, Honolulu, Hawaii (BPBM) as indicated. Material and methods The new species described herein were collected Taxonomy during the course of a comprehensive program of Genus Ischnura Charpentier aquatic biodiversity surveys on the islands of French Polynesia, recently undertaken in cooperation with Ischnura rurutana sp. n. the Délégation à la Recherche in Papeete, and Figs 2, 5, 8, 11–15, 23, 26, 29, 32 funded by that agency, with supplemental funding from the U. S. National Science Foundation. Col- Type material. – Holotype, ?: French Polynesia, lections at a given site were made by visual searching Austral Islands, Rurutu, Puputa Stream, above and hand netting of adults, and dip netting and kick Moerai Town, from water tanks at 64 m eleva- sampling of benthos for immatures. Specimens were tion (22.45016°S, 151.35100°W) upstream to preserved in 75% ethanol, then transported to the 80 m elevation at 20 m-high cascade (23.45041°S, Bishop Museum in Honolulu, Hawaii for detailed 151.35210°W), 23.xi.2003, BPBM-FP 1490, analysis and identification. R.A. Englund (BPBM). Paratypes: French Poly- All measurements are given in mm. Descriptive nesia, Austral Islands, Rurutu: 8 ?, 1 /, same data morphological terminology and associated abbrevia- as holotype (BPBM). tions used herein follow Westfall & May (1996) and Lieftinck (1959, 1966). Because the bright colors Description of these Ischnura fade considerably in specimens Male. Size. Dimensions of holotype: Total length preserved for any period of time, whether dry or in 30 mm; abdomen length 19 mm; fore wing length alcohol, our descriptions of coloration are based on 17 mm; hind wing length 16 mm. Intraspecific notes made from live individuals, dead individuals variation (n = 6): Total length 29–31 mm; abdomen immediately after capture, or photographs of living length 22­–26 mm; fore wing length 16–17 mm; specimens. hind wing length 15–16 mm. Scanning electron micrographs were made by the Colour (Fig. 2). Head. Labium beige; labrum green- second author using a Philips XL30 scanning elec- ish-blue; anteclypeus black; postclypeus bright blue .