Smicridea (Rhyacophylax) brasiliana (Ulmer, 1905)

Sganga, Julieta V., Sganga, Daniela E. & Iglesias, Monica S., 2022, Review and redescription of species in the brasiliana group of Smicridea (Rhyacophylax) (Trichoptera, Hydropsychidae, Smicrideinae): exploration of the utility of geometric morphometrics as a method for delimitation and characterization of species in the genus, ZooKeys 1111, pp. 389-412 : 389

Smicridea (Rhyacophylax) brasiliana (Ulmer, 1905)

Figs 1A , 3A-E

Smicridea (Rhyacophylax) brasiliana (Ulmer), 1905: 107 [as Rhyacophylax brasilianus ]. Weidner 1964: 97 [lectotype]. Flint 1966: 7 [invalid lectotype, misidentification]; 1972: 238 [discussion of lectotype]. Paprocki et al. 2004: 9 [checklist]; Paprocki and França 2014: 32 [checklist]. Holzenthal and Calor 2017: 165 [catalog].

Material examined.

Argentina • 1 male; Misiones, Río Iguazú, camp. Nandu ; 25 Feb. 1973; OS Flint Jr. det.; USNM .

Flint (1972) examined the type series of this species from the Ulmer collection (housed at the Zoologisches Museum Hamburg) where he found two mixed species, Smicridea (Rhyacophylax) brasiliana and another closely related species that he described as S. (R.) weidneri . The specimen we used for this redescription was collected in 1973 in Misiones province ( Argentina) and identified by Dr. Flint. This specimen was borrowed from the USNM .

Description.

Adult male. General color of the body light brown. Length of the forewings: 6.3 mm (n = 1). Coloration of the forewings similar to the body, with a subapical transverse, sinuous, white stripe, and a white, rectangular spot at midlength of the costal margin.

Head (Fig. 1A ). In dorsal view rectangular, transverse. Mesal margins of the eyes, in dorsal view, parallel, postgenal areas reduced. Interocular area rectangular, wider than long. Interocular distance 2.2 × shorter than MHW. Coronal suture 2/3 × shorter than IOD. Eyes lightly produced anteriorly, maximum eye width 3.3 × shorter than MHW. Anterolateral setose warts present, subtriangular, bifid posteriorly, mesal lobe shorter than the lateral. Posterior setose warts subtriangular. Maxillary palps missing.

Male genitalia. Anterolateral margin of segment IX rounded and produced (Fig. 3A ). Tergum of segment X triangular in lateral view, apex rounded, dorsal and ventral margins straight, the ventral one with a sclerotized H-shaped area directed anteriorly through segment IX (Fig. 3A ); in dorsal view divided mesally into two subtriangular hemitergites with apex subacute; internal margin of each hemitergite straight, with a concavity subapically (Fig. 3A, B ). Inferior appendages with two articules, setose, curved mesally in dorsal view; basal article narrow for a short distance proximally, from where it widens to the apex; apical article narrow, short, with rounded apex (Fig. 3B ). Phallus with long and tubular phallobase; basal portion broad, forming an angle of ~ 90° with distal part, which is slightly curved and with widened apex (Fig. 3A, C ); dorsal periphallic cap present subapically; apex of the phallus with a row of small spines extending from one side to the other ventrally, in dorsal view slightly produced laterally (Fig. 3A, C-E ). Internal sclerotized section of ejaculatory duct long and straight in lateral view (~ 2/3 the phallobase length), in dorsal view longitudinally divided in two (Fig. 3E ); distal end with an elongate, pointed dorsal plate, that bends upwards, then ventrad to the left at mid-length and upwards again, ending slightly beyond the tip of the ejaculatory duct; basally this plate bears a lateral spine; ventrally to the ejaculatory duct there are two spine-like plates and two lateroventral subrectangular plates that narrow posteriorly ending in a point (Fig. 3C-E ). Endotheca simple.

Systematic considerations.

This species seems to be related to S. weidneri and S. nanda . Genitalically, these species share the presence two pairs of elongate sclerites, dorsal and ventrad to the ejaculatory duct, which take different forms in the three species. Additionally, the morphology of the setose warts of the head of these species is similar, with the anterolateral setose warts bifid and the posterior ones triangular. Smicridea brasiliana can be distinguished by the presence of the elongate, sinuous, and pointed dorsal plate at the distal end of the ejaculatory duct, absent in the other two species, and the shape of the ventral plates that are spine-like, and the lateroventral ones that are subrectangular and pointed. Also, S. brasiliana has series of spines surrounding lateroventrally the end of the phallus, which are lacking in the other two species.

Distribution.

Argentina (new record), Brazil.

Figures

Figure 1. Heads in dorsal view of the species of the Smicridea brasiliana group A Smicridea (Rhyacophylax) brasiliana B S. (R.) weidneri C S. (R.) vermiculata D S. (R.) atrobasis E S. (R.) nanda. Abbreviations: CSL length of the coronal suture, IOD interocular distance, MEW maximum eye width, MHW maximum head width. Scale bar: 1 mm.

Figure 3. Male genitalia of Smicridea (Rhyacophylax) brasiliana A segments IX, X, inferior appendages and phallus, lateral view B segments IX, X and inferior appendages, dorsal view C tip of the phallus, lateral view (lateral spines removed) D tip of the phallus, dorsal view E tip of the phallus, ventral view.