Oecetis porntipae, Johanson & Pham & Malm & Sjöberg, 2020

Johanson, Kjell Arne, Pham, Thai Hong, Malm, Tobias & Sjöberg, Tin, 2020, Description of six new species of Oecetis (Trichoptera, Leptoceridae) from Vietnam, Zootaxa 4816 (3), pp. 311-324 : 317-318

Oecetis porntipae sp. nov.

Figs 16–20

Diagnosis. The species is distinguished from many of the Oriental and Palearctic species by the absence of honeycomb structure on pregenital tergites. In the genitalia, segment X is divided into a lower part and an upper part. The genitalia resemble those of Oecetis momos Malicky 2005 and Oecetis mekana Kimmins 1963 in the shape of the superior appendages, coxopodites, and tergum X. Oecetis porntipae sp. nov. is distinguished from O. momos by the broader and more symmetrically narrowing coxopodites in lateral view, the larger and more pointed cone shaped posterior dorsolateral process of segment IX, and the shorter superior appendages. It is separated from O. mekana by the presence of a complete longitudinal apodeme on the ventrolateral part of each side of segment IX, the basodorsal lobe on each gonocoxite, and a prominent lower posterolateral process on each side of segment IX.

Description, male. Length of each forewing 5.8 mm (N = 1). Genitalia ( Figs 16–20 ) slightly longer than high in lateral view. Segment IX oriented almost vertically, anterior margin slightly convex from dorsum to venter; dorsal part strongly narrowing posteriorly, curving slightly posterad; acrotergite of segment IX subtriangular, apically blunt, about as wide as each superior appendage in dorsal view; dorsal process of segment IX minute, forming pair of semimembranous papillae; sternum with large semimembranous area covering bases of coxopodites in ventral view; lower posterolateral process on each side of segment IX large, rhomboid; each upper posterolateral process of segment IX broadly cone shaped, about three times longer than superior appendages; longitudinal lateral apodeme present on each side ventrolaterally on segment IX, running from anterior margin to ventral corner of lower posterolateral process of segment IX. Tergum X much longer than superior appendages; in lateral view dorsal margins of upper part and lower part almost straight, ventral margin below upper part expanded into pair of membranous lobes, upper part tuboid; in dorsal view lower part with wide base, upper part almost parallel-sided along its length, with apex narrowly rounded. Superior appendages very short, broadly rounded in dorsal and lateral views, without membranous areas. Each gonocoxite in lateral view with broad base tapering to blunt apex, curving slightly dorsad after mid-length, about two times as long as tergum X, unbranched, with basidorsal lobe scarcely evident before mid-length, dorsal margin slightly undulating, ventral margin concave at mid-length; in ventral view narrowing sharply before mid-length; curving mesad beyond base; without large setae. Phallus almost as long as coxopodites, with about five small sclerites pointing posterad; phallobase with lateral process along right side hooked mesad apically.

Male holotype: Vietnam: Dong Nai Prov.: Vinh Cuu District, Vinh Cuu Nature Reserve, Ma Da stream, 11°22’38.2”N, 107°03’36.7”E, 78 m, light trap 16.iv.2011, loc#VN015, leg. KA Johanson & TT Du, DNA voucher JG5 ( VNMN in alcohol) .

Etymology. Porntipae, named for the trichopterologist Porntip Chantaramongkol, in recognition of her positive impact on the knowledge of the caddisfly diversity in the Oriental region.

Figures

FIGURES 16–20. Oecetis porntipae sp. nov., male holotype, genitalia. 16, left lateral; 17, dorsal; 18, ventral; 19, phallus, left lateral; 20, phallus, ventral. Scale bar = 0.1 mm.