Mayflies of the Fiji Islands (Ephemeroptera)

Material collected in 2024 in nine different rivers on the two main islands of Fiji, Viti Levu and Vanua Levu, is the basis for this taxonomic study of mayflies of the Fiji Islands. Apart from one larva of Caenidae, not treated in this study, all other larvae and three female imagos belong to two genera of the family Baetidae (<i>Baetis</i> Leach and <i>Papuanatula</i> Lugo-Ortiz & McCafferty). A new subgenus of <i>Papuanatula</i>, <i>Fijifiliola</i> <b>subgen. nov.</b>, based on the larvae of ten new species, and the larva and female imago of one new species of <i>Baetis</i> are described and illustrated. DNA barcodes (COI) were obtained for most species, and their genetic distances were analysed (Kimura-2 parameter). A key to all species of Papuanatula (Fijifiliola)<b>subgen. nov.</b> is provided. Amongst the new species of Papuanatula (Fijifiliola)<b>subgen. nov.</b>, a case of parthenogenesis and likely ovoviviparity is discussed.