Oecetis dorsospina, Johanson & Mary & Sjöberg & Malm, 2020

Johanson, Kjell Arne, Mary, Nathalie Jeanne, Sjöberg, Tin & Malm, Tobias, 2020, Eighteen new species of Oecetis McLachlan 1877 (Trichoptera, Leptoceridae) from New Caledonia, Zootaxa 4809 (2), pp. 201-240 : 217

Oecetis dorsospina sp. nov.

Figs 46–50

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 other Oecetis species by having a strongly prolonged posterior spine that is curved ventrad. It is separated from all other Oecetis species by its strongly projecting dorsal hump on each coxopodite.

Description, male. Length of each forewing 8.1 mm (N = 1). Genitalia ( Figs 46–50 ) slightly shorter than tall in lateral view. Segment IX oriented almost vertically, ventral part clearly longer than dorsal part in lateral view; on each side anterior margin convex along its length; posterior margin with upper posterolateral projection indistinguishable; with large lower posterolateral process of segment IX situated at mid-height of segment, forming 90° angle; longitudinal apodeme absent; acrotergite of segment IX weakly defined, forming pair of rounded punctate areas, each about as wide as upper part of tergum X in dorsal view; dorsal semimembranous processes of segment IX paired, very short, situated close to each other but separate; membranous areas absent.. Main branch of tergum X forming two short lobes, each reaching slightly further posteriorly than superior appendages, semimembranous, straight along its length, directed posterad, without apical setae; apex triangular in lateral view; in dorsal view lobes parallel-sided, with apices rounded. Posterior spine of tergum X originating at base of main branch, slightly narrower in basal one-third, curving ventrad at mid-length before dilated and rounded apex; in dorsal view parallelsided along most of its length, with pointed apex. Superior appendages short, tall, trapezoid in lateral view, ventral part pointing posterad, irregular in dorsal view. Each coxopodite in lateral view with broad base about as long as tall, dorsal hump strongly projecting into boomerang-shaped slender dorsal process; apicoventral corner pointed posterad; in ventral view coxopodites almost fused mesally for most of their length, separated by apicomedial cleft into V-shaped incision; large setae absent. Phallus as long as tergum X, in lateral view almost tuboid, anterior part slightly taller than posterior part, almost truncate anteriorly; in ventral view anteriorly rounded; several spines of different lengths and orientation situated inside phallus.

Male holotype: New Caledonia, Province Sud, Monts Dzumac, source stream of Ouinné River , near cross point to mountain track, 22°02.439’S, 166°28.646’E, 805 m, 18.xi–4.xii.2003, Malaise trap, loc#029, K.A. Johanson, DNA voucher JL1 .

Etymology. The Latin feminine noun in apposition dorsospina refers to the dorsal, spine-like process of each coxopodite.

Figures

FIGURES 46–50. Genitalia of Oecetis dorsospina sp. nov., male holotype. 46 left lateral; 47, dorsal; 48, ventral; 49, phallus, left lateral; 50, phallus, ventral.