Alterosa bilanceolata, Dumas, Leandro Lourenço & Nessimian, Jorge Luiz, 2013

Dumas, Leandro Lourenço & Nessimian, Jorge Luiz, 2013, New species of the caddisfly genus Alterosa Blahnik 2005 (Trichoptera: Philopotamidae: Philopotaminae) from Brazil, Zootaxa 3609 (1) : -

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.

Figures

FIGURE 3. Alterosa bilanceolata, new species, male genitalia. 3 A, left lateral view; 3 B, dorsal view (right intermediate appendage omitted); 3 C, left inferior appendage, dorsal view; 3 D, phallic apparatus, left lateral view; 3 E, phallic apparatus, dorsal view.