Setodes salweenensis, Laudee, Pongsak & Malicky, Hans, 2016

Laudee, Pongsak & Malicky, Hans, 2016, Three new species of Leptoceridae Leach 1815 (Insecta: Trichoptera) from Shan State, Myanmar, Zootaxa 4097 (2), pp. 263-270 : 267-268

Setodes salweenensis n. sp.

( Figures 9–12 )

Type material. Holotype male (PSUNHM). Myanmar: Shan State, Keng Tung Province, Naw-awn, Salween River, 21°13’46”N, 098°42’32”E, ca. 251 m a.s.l., 0 4 May 2015, leg. Sai Aye.

Paratypes: Same data as holotype, 18 males (PSUNHM); Myanmar: Shan State, Keng Tung Province, Nam Lok Stream, 21°22’50”N, 099°00’49”E, 442 m a.s.l., 0 3 May 2015, leg. Sai Aye, 5 males ( CHM).

Etymology. The species is named for the type locality, the Salween River.

Description. Length of each male forewing 6 mm (n=6); antennal length 11 mm; specimens in alcohol with head, thorax, abdomen and forewings light yellowish brown.

Male genitalia ( Figures 9–12 ). In lateral view ( Fig. 9 ), segment IX subtriangular and long ventrally; preanal appendages very small, triangular with small setae; segment X triangular, slightly curved downward; inferior appendages each 4-lobed: dorsal lobe tubular with long setae and erect basally then curved caudad, two mesal lobes tubular and 1/3 as long as dorsal lobe with first mesal lobe having long apical setae, basoventral lobe somewhat pentagonal with dorsal margin straight and ventral margin convex and apical margin truncate with small subapical setae. In dorsal view ( Fig. 10 ), segment X trapezoidal, basally slightly broader than apically, truncate apically with small spine in middle; preanal appendages small, oval, with short setae. In ventral view ( Fig. 11 ), segment IX subspherical; inferior appendages subrectangular, truncate apically. Phallus long, curved downward, pointed apically; pair of spine-like parameres long, curved downward, pointed apically ( Fig. 12 ).

Diagnosis. This species belongs to the Setodes argentiferus Group ( Schmid 1987, = S. argentiguttatus Group of Malicky & Chantaramongkol 2006). Among the species of that Group, the male genitalia of S. salweenensis n. sp. are most similar to those of S. omphale Malicky & Changthong 2006 (in Malicky & Chantaramongkol 2006), S. okypete Malicky & Chantaramongkol 2006 , S. okyrrhoe Malicky & Chantaramongkol 2006 , and S. opheltes Malicky & Chantaramongkol 2006 all from Thailand, S. venustus Ulmer 1951 from Sumatra, and S. bispinus Yang & Morse 1989 from China and Vietnam. All of these, including the new species, share the characteristics that segment X is triangular in lateral view and rectangular or trapezoidal in dorsal view, inferior appendages are 4- branched, and the phallus is long, curved downward, and pointed apically. However, the new species can be separated from the others by the character of the basoventral lobe of each inferior appendage. Setodes salweenensis n. sp. has a basoventral lobe that is pentagonal and is truncate apically in lateral view. In contrast, most of the other species have this basoventral lobe triangular and pointed apically. This lobe can be obliquely truncate in S. venustus ( Ulmer 1951, pl. 21 fig. 649), but the preanal appendages are not apparent in the latter species and its tergum X is rectangular in dorsal view (trapezoidal in S. salweenensis n. sp.).

Figures

FIGURES 9 – 12. Male genitalia of Setodes salweenensis n. sp. 9, genitalia, left lateral; 10, segment IX, preanal appendages, and segment X, dorsal; 11, segment IX and inferior appendages, ventral; 12, phallus, left lateral.