Simulium mariavulcanoae Coscarón & Wygodzinsky, 1984,

Gil-Azevedo, Leonardo H. & Molina, Óscar Sánchez, 2016, New synonymy to Simulium (Inaequalium) diversibranchium Lutz, with comments on the Inaequale species-group (Diptera, Simuliidae), Revista Brasileira de Entomologia 60 (4), pp. 293-296 : 294-295

Simulium mariavulcanoae Coscarón & Wygodzinsky, 1984 syn. n.

Taxonomic remarks. Despite many revisionary works about Simulium (Inaequalium) ( Coscarón, 1991; Coscarón and Coscarón-Arias, 2007; Coscarón and Wygodzinsky, 1984; Hernández-Triana et al., 2007b; Shelley et al., 2010; Strieder and Py-Daniel, 2000, 2002), still only one character of pupal gill shape separates S. diversibranchium from S. mariavulcanoae : “secondary branches of ventral primary branch downwards and posteriorly directed”; in contrast with the other species in which those branches are anteriorly directed. But those authors agree that both species are close, and could be grouped by sharing a single character of the pupal gill shape: “dorsal primary branch thicker than other primary branches”.On the other hand, S.mariavulcanoae lacks unique exclusive characters, making the species meaningless.

This single character currently separating S. diversibranchium and S.mariavulcanoae is not consistent and could be caused by environmental influences in the pupal development. There is, however, not many specimens for examination, the species being rare. But we found an interesting pupa from Pedralva (MG), which could be identified either as S. diversibranchium , or as S. mariavulcanoae depending if the left (Fig. 3), or the right (Fig. 4) side is examined. This is evidence that the direction of gill filaments is not a reliable character.

Lutz (1910) described S. diversibranchium based on pupae syntypes. In a review of Simulium (Inaequalium), Hernández-Triana et al. (2007b) chose one of the pupae syntypes and raised it to lectotype status of the species. We examined this, and the gill does not have the secondary branches of ventral primary branch downward and posteriorly directed, but all branches are anteriorly directed ( Fig. 1 ). The lectotype of S. diversibranchium does not match the description of this species in the literature, but with the description and the types of S. mariavulcanoae ( Coscarón and Wygodzinsky, 1984) (Fig. 2). So, both names refer to the same entity, and we propose that S. mariavulcanoae is a junior synonym of S. diversibranchium .

Diagnosis (based only on pupa) (modified from Coscarón and Coscarón-Arias, 2007: 286). Frontoclypeus and thorax with abundant tubercles; trichomes of frontoclypeus with 2–6 branches, thoracic trichomes with 5–8 branches. Gill with 6 filaments in three primary branches: dorsal primary branch distinctly thicker than medial and ventral primary branch; the most ventral secondary branch (from ventral primary branch) could be downward and posteriorly directed, or directed as the other secondary branches; gill length 2.8–3.5 mm. Cocoon with thin weave, with few evident threads, reinforced edge and slowly projected ventrally; cocoon length on base 3.2–4.0 mm, on dorsum 2.6–3.5 mm.

Distribution. Argentina, Misiones: Campiña. Brazil, RS: Caxias do Sul; Bom Jesus. SC: São Bento do Sul; Joinville. SP: Selesópolis, Estação Biológica de Boraceia; Itu; Capivari; Bragança Paulista; Campos do Jordão; São José do Barreiro, Serra da Bocaina, Fazenda do Bonito; Ocauçu (as Casagrande). RJ: Guapimirim; Petrópolis; Itatiaia. MG: Bocaina de Minas.

Figures

Fig. 1. Pupal gill branches of Simulium (Inaequalium) diversibranchium (=S. mariavulcanoae), in slides (1–5; 10–12): (1) CSIOC #12,097 Lutz collection (Lectotype); (2) MLP #115,232 (paratype of S. mariavulcanoae); (3) CSIOC #3,109 left gill; (4) CSIOC #3,109 right gill; (5) MNRJ #60,020; (10) CSIOC #3,780; (11) CSIOC #3,986; (12) CSIOC #4,448. Pupal gill branches of Simulium (Inaequalium) subnigrum, in slides (6–9): (6) MNRJ #60,002; (7) MNRJ #60,007; (8) MNRJ #60,010; (9) MNRJ #60,012.