Oecetis oxybelis, 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 : 215-217

Oecetis oxybelis sp. nov.

Figs 41–45

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 simple coxopodites curving slightly dorsad in lateral view, and tergum X divided into a simple dorsal posterior spine and a bilobed main branch. It particularly resembles Oecetis alicae sp. nov. in the shape of the coxopodites being narrow and with a dorsal hump at mid-length in lateral view. The shape of the posterior spine resembles that of Oecetis dorsospina sp. nov. in dorsal view. Oecetis oxybelis sp. nov. is easily distinguished from O. alicae sp. nov. in the much longer posterior spine; and from O. dorsospina sp. nov. in the more-slender posterior spine in lateral view and much shorter dorsal hump of each coxopodite.

Description, male. Length of each forewing 4.9–7.0 mm (N = 8). Genitalia ( Figs 41–45 ) slightly longer than tall in lateral view. Segment IX oriented almost vertically, ventral part nearly twice as long as dorsal part in lateral view; on each side anterior margin convex at mid-height; posterior margin slightly expanded posteriorly by small lower posterolateral process immediately above base of coxopodite; upper posterolateral projection indistinguishable; longitudinal apodeme absent; acrotergite of segment IX weakly defined, apparently forming a continuous area about half as wide as segment IX in dorsal view; dorsal semimembranous processes of segment IX paired, very short, situated close to each other but separated; membranous areas absent. Main branch of tergum X forming two lobes, each reaching slightly further posteriorly than superior appendages, semimembranous, straight along their length, directed posterad, each with one apical seta; tapering to very narrow apex in lateral view; in dorsal view each lobe slightly tapering towards widely rounded apex, curving slightly laterad along their length. Posterior spine of tergum X originating at base of main branch, slightly narrower than superior appendages in lateral view, parallel-sided finger-like, curving ventrad before pointed apex; in dorsal view nearly parallel-sided along its length, with rounded apex. Superior appendages short, subrectangular in lateral view, oval in dorsal view. Each coxopodite in lateral view curving slightly dorsad along its length, basal half almost parallel-sided, clearly taller than posterior half, rounded subtriangular dorsal hump present on dorsal margin at mid-length; in ventral view without mesal plate at base or at mid-length; basally broad and tapering along their length, curving mesad towards apex; without large setae. Phallus as long as rest of genitalia, drop-shaped, anterior part tall and rounded, in ventral view anterior part wide, irregular in shape, slightly narrowing posteriorly; long, slender inner spine starting from upper right part of anterior apex, running through phallus at mid-height and to the left margin before escaping posterior apex; posterior apex with ventral plate curving ventrad.

Male holotype: New Caledonia, Province Sud, Monts des Koghis, ca. 800 m S Koghi Restaurant , 22.18406°S ,

166.50383°E, 420 m, 11–26.xi.2003, Malaise trap, loc#022, leg. K.A. Johanson, DNA voucher JH3.

Paratypes: 2 males, 1 female: same data as holotype, except DNA vouchers JH2, JH3, JH4 . 1 male: New Caledonia, Province Sud, Monts des Koghis, ca. 800 m S Koghi Restaurant , 22.18365°S, 166.50451°E, 440 m, 11–26.xi.2003, Malaise trap, loc#021, leg. K.A. Johanson, DNA voucher JL6 .

1 male: New Caledonia, Province Sud, Plateau de Dogny, Source of Dogny River, about 1.2 km SE summit of Plateau , about 200 m from waterfall, 21.62067°S, 165.88290°E, 915 m, 25.xi–16.xii.2003, Malaise trap, loc#048, leg. K.A. Johanson, DNA voucher JK6 . New Caledonia, Province Sud, Monts des Koghis , ca. 300 m S Koghi Restaurant, 22.18288°S, 166.50490°E, 457 m, 06.xii.2001, light trap, loc#001c (07-2001), leg. K.A. Johanson, T . Pape, B. Viklund, DNA voucher AH7. 1 male: New Caledonia, Province Sud, Monts des Koghis , ca. 300 m S Koghi Restaurant, 22.18288°S, 166.50167°E, 417 m, 16–26.xi.2003, Malaise trap, loc#004, leg. K.A. Johanson, DNA voucher JQ4 . 1 male: New Caledonia, Province Sud, Monts des Koghis , ca. 300 m S Koghi Restaurant, 22.18288°S, 166.50393°E, 447 m, 16–26.xi.2003, Malaise trap, loc#002a, leg. K.A. Johanson, DNA voucher AM8 .

Etymology. The Greek masculine noun in apposition oxybelis , refers to the genus Oxybelis, a vine snake, after the shape of the posterior spine in lateral view, resembling the forepart of the vine snake.

Figures

FIGURES 41–45. Genitalia of Oecetis oxybelis sp. nov., male holotype. 41, left lateral; 42, dorsal; 43, ventral; 44, phallus, left lateral; 45, phallus, ventral.