Rhyacopsyche dikrosa, Wasmund, Anne M. & Holzenthal, Ralph W., 2007

Wasmund, Anne M. & Holzenthal, Ralph W., 2007, A revision of the Neotropical caddisfly genus Rhyacopsyche, with the description of 13 new species (Trichoptera: Hydroptilidae), Zootaxa 1634, pp. 1-59 : 11-12

Rhyacopsyche dikrosa , new species

Fig. 13

This species resembles R. hagenii in general form. Both R. hagenii and R. dikrosa possess bifid dorsolateral lobes, a midlateral lobe on segment IX, and a single large apical seta on the inferior appendage. The elaborately developed, forked dorsolateral lobes of R. dikrosa are unique among all Rhyacopsyche species. In addition, this is the only species with long peglike setae present on tergum X and a basally bifid inferior appendage.

Adult (male: n=11, female: n=12). Forewing length 2.9–3.5, 3.1 mm (male), 3.0–4.0, 3.5 mm (female). Color of head dark brown, antennae light brown, legs medium brown, wings mottled medium and dark brown. Sternum VII with apicomesal point.

Male genitalia. Abdominal segment IX heavily setose, anterior margin deeply rounded; sternum IX, in lateral view, with posterior margin produced into small rounded process; posterior margin produced into small rounded lobe bearing short, thick setae; dorsolateral lobe of segment IX elongate, in dorsal view narrowed, deeply divided, widely separated, terminating in large fork, the ventral lobe bearing 1 short peglike seta. Tergum X partially retracted inside segment IX, apex rounded, bearing several long, dark, thick setae. Intermediate appendage not evident. Inferior appendage elongate, heavily setose, base bifid, dorsal lobe long and narrow, ventral lobe larger, rounded, bearing 1 large pointed seta. Phallus linear, thin membranous sheath surrounding virtually the entire phallus, covered with spicules; central tubule with two opposing apical hooks; apex of lateral process rounded.

Holotype male: BRAZIL: São Paulo: Pedregulho, 140 km NE Ribeirao Preto, 20.iii.1989, L G Oliveira — 1 male ( UMSP 000115164) ( MZUSP).

Paratypes: BRAZIL: Minas Gerais: Parque Estadual Itacolomi, Rio Belchior, 20°25’02”S, 043°25’38”W, 725 m, 2.ii.1998, Holzenthal & Paprocki — 2 males ( MZUSP); 17.xii.1998, Paprocki & Amarante — 2 males, 3 females ( UMSP); Corrego Pitanga, upstream of confluence with Rio Santo Antônio, 19°05’40”S, 042°39’54”W, 238 m, 19.x.2000, Paprocki & Ferreira — 1 male ( UMSP); Rio de Janeiro: Nova Friburgo, municipal water supply, 950 m, 24.iv.1977, C M & O S Flint — 1 male ( NMNH); Rio Sousa, in Cachoeiras de Macacú, 26°26’34”S, 042°37’57”W, 150 m, 16.iii.1996, Holzenthal, Rochetti & Oliveira — 1 male ( MZUSP); São Paulo: Estação Biológica Boraceia, Rio Guaratuba, 23°40’02”S, 045°53’46”W, 775 m, 17.iv.1998, Holzenthal, Melo & Froehlich — 3 males, 8 females ( UMSP); Rio Coruja, 23°40’06”S, 045°53’57”W, 850 m, 18.iv.1998, Holzenthal, Melo & Froehlich — 1 male, 1 female ( MZUSP).

Distribution. Brazil.

Etymology. The Greek word dikros, meaning forked, referring to the prominent fork of the dorsolateral lobe of segment IX.

Figures

FIGURE 13. Rhyacopsyche dikrosa, new species. Male genitalia: A—lateral; B—dorsal; C—ventral; D—phallus, dorsal.