Oecetis ramosa, 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 : 205-207

Oecetis ramosa sp. nov.

Figs 11–15

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 ovula sp. nov. in the sigmoid shape of the coxopodites. Oecetis ramosa sp. nov. is distinguished from O. ovula sp. nov. in the much longer and apically bifid superior appendages, the more slender posterior spine of tergum X, the longer main branch of tergum X, and the more slender coxopodites in lateral and ventral views.

Description, male. Length of each forewing 7.0– 7.6 mm (N = 3). Genitalia ( Figs 11–15 ) slightly longer than tall in lateral view. Segment IX oriented almost vertically, ventral part much longer than dorsal part; on each side anterior margin slightly convex; lower posterolateral process of segment IX not distinguishable from posterior margin; upper posterolateral process of segment IX weakly developed, fused with basal part of tergum X; longitudinal apodeme absent; acrotergite of segment IX bilobed, punctate, almost as wide in dorsal view as length of ventral part of segment IX in dorsal or lateral views; dorsal semimembranous processes of segment IX minute, well separated, wart-like; membranous areas absent. Main branch of tergum X almost as long as superior appendages, semimembranous; dorsal margin convex in lateral view; ventral margin concave; apex curving ventrad, blunt in lateral view; in dorsal view each lobe basally wide, narrowing and acute apically, diverging from mid-length. Posterior spine of tergum X originating at base of main branch, finger-like, gradually curving slightly ventrad, not exceeding main branch posteriorly. Superior appendages long, slender, gradually curving ventrad along their length, each with bifurcating apex, slightly sigmoid in dorsal view. Each coxopodite sigmoid, distal half straight; slightly exceeding tergum X posteriorly; basal part wide in ventral view, without mesal plate, directed posterolaterad basally before bending posterad after mid-length, with rounded apex, lacking large setae. Phallus about as long as rest of genitalia, anterior part very broad, drop-shaped in ventral view, slightly tapering posteriorly along its length in lateral view; large spine originating from right anterior part, curving strongly inside anterior margin and left side before ending in posterior part, apically curving slightly posteroventrad.

Male holotype: New Caledonia, Province Nord, Mont Panié , stream at camp, 20.58167°S, 164.76472°E, 1311 m, 9.xii.2003, Malaise trap, loc#073, leg. K.A. Johanson, DNA voucher JE7 . Paratypes: 2 males: same locality data as holotype, DNA vouchers AO6 and JB7. Etymology. The Latin adjective ramosa , means “branched,” “bifid,” or “forked,” referring to the bifid apex of each superior appendage .

Figures

FIGURES 11–15. Genitalia of Oecetis ramosa sp. nov., male holotype. 11, left lateral; 12, dorsal; 13, ventral; 14, phallus, left lateral; 15, phallus, ventral.