Alterosa bilanceolata Dumas & Nessimian, 2013, new species
Creators: name: Dumas, Leandro Lourenço
name: Nessimian, Jorge Luiz
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Trichoptera
Philopotamidae
Alterosa
Alterosa bilanceolata

description: Alterosa bilanceolata, new species
Figs. 3 A–E
Alterosa bilanceolata sp. nov. cannot be placed in any of the species groups defined by Blahnik (2005). The new species is easily diagnosed by the shape of the preanal appendages, which are knife-like and bear long setae as viewed laterally. Additionally, the greatly modified structure of the phallobase is also a useful diagnostic character for this species.
Adult. Color (in alcohol) dark brown; legs, palps, and antennae light brown, wing pattern not discernible. Male forewings each 5.8 mm (n=1).
Male genitalia. Tergum VIII with posteromesal margin scarcely or not emarginate. Sternum IX with anterolateral margins forming rounded projection on each side in dorsal half; posteroventral margin produced, forming broadly rounded expansion (Fig. 3 A). Tergum IX greatly reduced, membranous or fused to base of tergum X (Fig. 3 B). Tergum X in dorsal view narrow, enlarged at base, with margins weakly protruding, subparallel; apex sensillate, subtruncate in dorsal view, rounded and slightly enlarged in lateral view (Figs. 3 A, 3B). Intermediate appendages heavily sclerotized, elongate, extending past preanal appendages, rod-like, rounded apically, covered by short, small setae (Figs. 3 A, 3B). Preanal appendages enlarged, each with row of long setae on external margin, enlarged at basal third as viewed dorsally, knife-like in lateral view; apex subacute (Figs. 3 A, 3B). Inferior appendages elongate, setose; each with 1st article, in lateral view, approximately 2 times as long as wide, slightly wider at base; 2nd article shorter than 1st article, relatively wide, base nearly as wide as apex of 1st article, narrowed subapically; apex rounded, with small pad of short, stiff apicomesal setae (Figs. 3 A, 3C). Phallobase tubular, relatively short, very slightly curved, enlarged from midlength to apex as viewed dorsally, greatly modified; posteroventral margins with 2 long spear-like projections, acute apically; posterodorsal margin greatly emarginate, with V-shaped emargination and paired stout spines as viewed dorsally; endotheca without evident spines or phallotremal sclerites (Figs. 3 D, 3E).
Holotype male: BRAZIL: Paraná: Guaraqueçaba, Ribeirão do Engenho, 25°10’31.0”S, 48°22’16.2”W, el. 25 m, 25.i.2011, JL Nessimian & LL Dumas leg. (DZRJ 3481).
Distribution: Brazil (Paraná state).
Etymology: The epithet of the specific name, bilanceolata, is from the Latin word lanceola (small spear) and the prefix bi- (two, paired), referring to the greatly modified phallobase, which bears paired, apically spear-like projections on the posteroventral margin.
description: Published as part of Dumas, Leandro Lourenço & Nessimian, Jorge Luiz, 2013, New species of the caddisfly genus Alterosa Blahnik 2005 (Trichoptera: Philopotamidae: Philopotaminae) from Brazil in Zootaxa 3609 (1), DOI: 10.11646/zootaxa.3609.1.2, http://zenodo.org/record/217702