Byrsopteryx espinhosa Harris & Holzenthal, 1994

Santos, Allan Paulo Moreira & Nessimian, Jorge Luiz, 2010, Description of a new species of Byrsopteryx (Trichoptera: Hydroptilidae) from Rio de Janeiro State, Brazil, including its immature stages, Zootaxa 2668, pp. 44-54 : 52-54

Byrsopteryx espinhosa Harris & Holzenthal, 1994

( Figs. 25–27 , 28–29 )

Byrsopteryx espinhosa Harris & Holzenthal 1994 [type locality: Brazil, Rio de Janeiro, km 17, 18 km S Teresópolis; male described; holotype depository: MZSP].

Female. Length 3.2–3.6 mm. Antennae simple, short, 16-articulated. General color black, forewing with 3 white spots. Wing venation reduced, forewing with distinct “line of weakness” Abdominal segment VI without ventromesal process.

Female genitalia. Segment VII elongate, covered ventrally with short plumose setae ( Fig. 28 ). Segment VIII broader than long, posterior margin with row of stout setae; internally with a pair of elongate lateral apodemes extending to anterior of segment VII ( Fig. 28 ). Segment IX short, internally with a pair of elongate lateral apodemes extending to middle of segment VII. Segment X short, wide basally, narrowing to truncate apex, bearing a pair of papillae ( Fig. 28 ). Vaginal apparatus with anterior portion lightly sclerotized, with anterior margin rounded; posterior portion wide, with elaborate, membranous folds ( Fig. 29 ).

Larva (final instar). Length 2.6–3.6 mm (n=16). Head and sclerites of thorax and abdomen brown or dark brown. Other morphological features ( Fig. 25, 26 ) similar to those described for larva of B. carioca sp. nov.

Larval case. Length 2.4–3.1 mm (n=16). Made entirely of silk with bits of mineral material incorporated; slightly depressed dorsoventrally, with poorly closed dorsal seam; anterior and posterior openings circular.

Pupa. Length 2.6–3.0 mm (n=30). Morphological features similar to those described for pupa of B. carioca sp. nov.

Pupal case. Length 3.6–3.8 mm (n=30). Anterior end (corresponding to posterior end of larval case) with short ventral stalk, attaching pupal case to substrate. Anterior margin truncate; posterior margin rounded. Pupal case laterally compressed ( Fig. 27 ).

Remarks. This species was previously known from only the holotype from Rio de Janeiro State, Brazil. Additional material was recently collected in Teresópolis, Rio de Janeiro State. Larvae and pupae were collected in the Rio Paquequer, where a large number of specimens were found immediately upstream of the small waterfall. Larvae and pupae occurred in groups in the splash zone, and occasionally were located above the water line. Adults exhibited the active running behavior seen in other species, including rotating the body around the axis of the head.

Females of B. espinhosa can be distinguished from others in the genus by the vaginal sclerite having the anterior portion slightly sclerotized and rounded and the posterior portion membranous, with numerous folds.

Although the larva of B. espinhosa has been associated, it is very similar to the larva of B. abrelata and of B. carioca . sp. nov. The larva of B. espinhosa is lighter in color than the larvae of B. carioca sp. nov. and B. abrelata . However, larvae of the 3 species are otherwise almost identical and can be identified with confidence only when adults are collected in the same locality.

Material examined. Brazil, Rio de Janeiro State, Teresópolis: Parque Nacional da Serra dos Órgãos, Rio Paquequer, Cachoeira do Coreto, 22°26’51.6”S 42°59’04.9”W, 933 m, 19.v.2009, A.P.M. Santos leg., 1 male, 13 pharate adults, 30 pupae, 16 larvae ( DZRJ); same data, except, 04.vi.2009, 8 males, 5 females ( DZRJ).

Distribution. Rio de Janeiro State, Brazil.

Figures

FIGURES 18 – 27. Larvae and cases of Byrsopteryx spp. Figs. 18 – 21, Byrsopteryx carioca sp. nov. 18: larva and case, dorsal view; 19: larva and case, left lateral view; 20: larva, left lateral view; 21: pupal case, left lateral view. Figs. 22 – 24, Byrsopteryx abrelata. 22: larva and case, left lateral view; 23: larva, left lateral view; 24: pupal case, left lateral view. Figs. 25 – 27, Byrsopteryx espinhosa. 25: larva and case, left lateral view; 26: larva, left lateral view; 27: pupal case, left lateral view. Scale bar = 0.5 mm.

FIGURES 28 – 29. Byrsopteryx espinhosa, female genitalia. 28: terminal segments of abdomen, ventral view; 29: vaginal apparatus, ventral view. Scale bar = 0.1 mm.