Eighteen new species of Oecetis McLachlan 1877 (Trichoptera, Leptoceridae) from New Caledonia Author Johanson, Kjell Arne * kjell. arne. johanson @ nrm. se; https: // orcid. org / 0000 - 0002 - 1893 - 3429 & * kjell. arne. johanson @ nrm. se; https: // orcid. org / 0000 - 0002 - 1893 - 3429 Author Mary, Nathalie Jeanne ETHYC’O, B. P. 13821, 98 803 Nouméa Cedex, Nouvelle-Calédonie. & ethyco 2005 @ gmail. com; https: // orcid. org / 0000 - 0001 - 8250 - 7929 Author Sjöberg, Tin * kjell. arne. johanson @ nrm. se; https: // orcid. org / 0000 - 0002 - 1893 - 3429 & tin. sjoberg @ nrm. se; https: // orcid. org / 0000 - 0002 - 2813 - 9325 Author Malm, Tobias * kjell. arne. johanson @ nrm. se; https: // orcid. org / 0000 - 0002 - 1893 - 3429 & tobias. malm @ nrm. se; https: // orcid. org / 0000 - 0003 - 4610 - 4086 text Zootaxa 2020 2020-07-07 4809 2 201 240 journal article 10.11646/zootaxa.4809.2.1 1175-5326 3934048 E697983F-7223-4009-91B4-80A401D0AB8A Oecetis amphora sp. nov. Figs 1–5 Diagnosis. The species is distinguished from many of the Australasian Oecetis species by the absence of modified tergites V–VIII. It resembles Oecetis atarpa Mosely 1953 (in Mosely & Kimmins 1953 ) in the genitalia, particularly the shape of the coxopodites in lateral view. In lateral view, each coxopodite is almost symmetrically broad basally, with a long, slender, slightly dorsad-turning branch originating from the apical center of the basal portion. Oecetis amphora sp. nov. is distinguished from O. atarpa in the longer superior appendages, presence of a posterior spine, and coxopodites in ventral view being less strongly curved mesad. Description, male. Length of each forewing 4.3–5.5 mm (N = 2). Genitalia ( Figs 1–5 ) about as tall as long in lateral view. Segment IX oriented almost vertically, ventral part slightly longer than dorsal part and slightly produced posteriorly; dorsal part oriented vertically; on each side its anterior margin almost straight; posterior margin dominated by well-developed posterolateral processes; lower posterolateral process tall, short; upper posterolateral process long, fusing with lower part of tergum X; longitudinal apodeme horizontal between lower posterolateral process and anterior margin of segment IX; acrotergite of segment IX well developed, punctate, slightly wider than each superior appendage in dorsal view; dorsal semimembranous processes of tergum IX minute, wart-like; segment IX without membranous areas. Main branch of tergum X about twice as long as superior appendages, semimembranous, divided subapically into pair of divergent branches; dorsal margin slightly convex in lateral view; ventral margin concave in lateral view; apex curving ventrad, sharply pointed in lateral view; in dorsal view branches wide, slightly diverging posteriorly and pointing laterad at apices. Posterior spine of tergum X originating at mid-length of main branch, straight, finger-like. Superior appendages wide, short, almost rectangular in lateral and dorsal views. Each coxopodite, in lateral view, divided into nearly symmetrical basal half and slender distal half, distal half originating from mid-height of apex of basal half and curving slightly dorsad in lateral view and mesad in ventral view; exceeding tergum X posteriorly, lacking large setae. Phallus about as long as coxopodites, curving ventrad along its length, symmetrical, without spines and processes; in ventral view nearly parallel-sided. FIGURES 1–5. Genitalia of Oecetis amphora sp. nov. , male genitalia. 1 , left lateral; 2 , dorsal; 3 , ventral; 4 , phallus, left lateral; 5 , phallus, ventral. Male holotype : New Caledonia , Province Sud , Monts Dzumac , source stream of Ouinné River , downstream cross point to mountain track, 22°01.997’S , 166°28.486’E , 795 m , over about 30 m waterfall, 18.xi–4.xii.2003 , Malaise trap , loc#031, leg. K.A. Johanson , DNA voucher JL3 . Paratype : 1 male : New Caledonia , Province Nord , Mont Panié , River Padyéém , 400 m , Malaise trap , 20°34.122’S , 164°48.147’E , 22–28.xi.2001 , loc 146 (16-2001), leg. K.A. Johanson , T . Pape, B . Viklund, DNA voucher AG6 . Etymology. The Latin feminine noun in apposition amphora , means “vase”, referring to the shape of the coxopodites in lateral view.