Oecetis christinae, 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 : 210-212

Oecetis christinae sp. nov.

Figs 26–30

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 and slightly sigmoid or undulating coxopodites in lateral view and tergum X divided into a simple dorsal posterior spine and a bilobed branched main branch. It particularly resembles Oecetis loyolaensi sp. nov. and Oecetis millei sp. nov. in the slightly sigmoid shape of the coxopodites, lacking a dorsal process, but having a basimesal plate seen in ventral view. It also resembles O. rostrata sp. nov. in having a small mesal plate originating from the dorsal margin of the coxopodites, and a short spine on the apicodorsal part of phallus. Oecetis christinae sp. nov. is distinguished from both O. loyolaensi sp. nov., and O. millei sp. nov. in having a pair of main branches of tergum X that are much longer than the posterior spine, the presence of a small rounded triangular upper posterolateral projection of segment IX situated immediately below the superior appendage on each side, and the phallus having a strong inner spine being nearly straight in lateral view and curving to the right in ventral view. It is separated from O. rostrata sp. nov. by having broader coxopodites in lateral view, more rounded mesal plates at the mid-length of the coxopodites, and a dorsal phallic spine that is more-slender and about straight in lateral view.

Description, male. Length of each forewing 9.2 mm (N = 1). Genitalia ( Figs 26–30 ) slightly longer than tall in lateral view. Segment IX oriented almost vertically, ventral part clearly longer than dorsal part; on each side anterior margin weakly angled below mid-height; posterior margin dominated by well-developed upper and lower posterolateral processes of segment IX, situated immediately below superior appendages and near dorsobasal part of coxopodites, respectively; longitudinal apodeme slender, running between anterior and posterior margins of segment IX at mid-height of coxopodite base; acrotergite of segment IX large, punctate, almost as wide as half the width of segment IX in dorsal view; dorsal semimembranous processes of segment IX paired, minute, closely situated, wart-like; membranous areas absent. Main branch of tergum X forming two lobes longer than posterior spine and about twice as long as superior appendages, semimembranous, straight, directed posteroventrad, without setae; apices drop-shaped in lateral view; in dorsal view each lobe tapering towards pointed apex, oriented posterad. Posterior spine of tergum X originating at base of main branch, slender, finger-like, as thick as central part of main branch in lateral view, almost straight. Superior appendages short, oblong in lateral view, almost straight, in dorsal view broadly oval. Each coxopodite in lateral view slightly sigmoid shaped, basally wide to beyond mid-length, bending posterad and slender immediately after mid-length; distal part almost straight; clearly exceeding tergum X posteriorly; in ventral view basal-most part wide, with large, rounded triangular mesal plates; dorsal part with rounded mesal plate at mid-length, without large setae. Phallus about as long as coxopodites, tall along its length, anterior margin right-angled, posteriorly with membranous tissue not expanded; inner spine starting from anterior apex, straight along its length in lateral view, apex slightly exceeding posterior margin; in ventral view parallelogram shaped, narrow anteriorly and posteriorly.

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 JB8 .

Etymology. The species is named christinae for Dr. Christine Pöllabauer, in recognition of her work on New Caledonian Trichoptera diversity.

Figures

FIGURES 26–30. Genitalia of Oecetis christinae sp. nov., male holotype. 26, left lateral; 27, dorsal; 28, ventral; 29, phallus, left lateral; 30, phallus, ventral.