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 ovula sp. nov. Figs 6–10 Diagnosis. The species is distinguished from many of the Australasian Oecetis species by the absence of modified tergites on segment VIII and forward. It resembles many Oecetis species in the presence of simple and slightly sigmoid-shaped coxopodites in lateral view. It particularly resembles Oecetis ramosa sp. nov. in the sigmoid shape of the coxopodites. Oecetis ovula sp. nov. is distinguished from O. ramosa sp. nov. in the much shorter and oval shape of the superior appendages, the thicker posterior spine of tergum X, shorter main branch of tergum X, the thicker coxopodites in lateral view, and the more sinuous inner margins of the coxopodites in ventral view. Description, male. Length of each forewing 6.8 mm (N = 1). Genitalia ( Figs 6–10 ) slightly longer than tall in lateral view. Segment IX oriented almost vertically, ventral part slightly longer than dorsal part; on each side anterior margin slightly convex; posterior margin dominated by well-developed lower posterolateral process of segment IX tall, broadly triangular above coxopodite base; upper posterolateral process absent; longitudinal apodeme absent; acrotergite of segment IX well developed, punctate, about as wide as length of superior appendages in dorsal view; segment IX with dorsal semimembranous processes minute, wart-like; membranous areas absent. Main branch of tergum X about twice as long as superior appendages, semimembranous; dorsal margin almost straight in lateral view; ventral margin indistinguishable; apex curving ventrad in lateral view; in dorsal view divided subapically into pair of divergent lobes, each lobe wide, almost parallel-sided, with rounded apex. Posterior spine of tergum X originating at base of main branch, finger-like, slightly curving ventrad, slightly exceeding main branch posteriorly. Superior appendages wide, short, drop-shaped in lateral view, ovoid in dorsal view. Each coxopodite sigmoid-shaped, distal half curving slightly ventrad; strongly exceeding tergum X posteriorly; in ventral view with wide, rounded mesal plate before mid-length, gently curving mesad from distal one-third, with rounded apex, lacking large setae. Phallus about as long as coxopodites, anterior part very tall and broad, tapering posteriorly along its length; large spine originating from anterodorsal part, curving first ventrad and then caudad; in ventral view, originating at left side and curving posterad on right side. Male holotype : New Caledonia , Province Sud , Tamoa River , 700 m S road RT1 between Nouméa and La Foa , 22°04.518’S , 166°16.592’E , 19.xi.2003 , light trap , loc#033, leg. K.A. Johanson , DNA voucher JK9 . Etymology. The Latin feminine noun in apposition ovula , means small egg, referring to the shape of the superior appendages in dorsal view.