Simulium (Hemicnetha) rivasi Ramírez Pérez, 1971

HERNÁNDEZ, LUIS MIGUEL, SHELLEY, ANTHONY JOHN, DE LUNA DIAS, ANTONIO PAULINO ANDRADE & MAIA-HERZOG, MARILZA, 2007, New specific synonymies and taxonomic notes on Neotropical black flies (Diptera: Simuliidae) belonging to the subgenera Chirostilbia Enderlein, Hemicnetha Enderlein, Inaequalium Coscarón & Wygodzinsky, Psaroniocompsa Enderlein and Psilopelmia Enderlein, Zootaxa 1506 (1), pp. 1-80 : 11

Simulium (Hemicnetha) rivasi Ramírez Pérez, 1971

( Figs. 208–210 )

Simulium rivasi Ramírez Pérez, 1971: 359 . HOLOTYPE [Life stage not indicated in original description.], VENEZUELA: Mérida State, Nacimiento del Rio Chama , entre el Páramo El Aguila? y Apartaderos; [No date or collector’s name given in the original description.] (DERM) [Location of the holotype unknown-see Note on Ramírez Pérez’ Simuliidae collection in Materials and Methods.]

Simulium rivasi [subsequently misspelled as rivai and ribai in Ramírez Pérez, 1971] was described by Ramírez Pérez in 1971 from specimens collected in Venezuela, but he did not state which life stage had been designated as the holotype. He figured and described the female, and provided illustrations of the male genitalia, morphology of the gill filaments, cephalic and thoracic trichomes of the pupa, head capsule and hypostomium of the larva. In the original description, Ramírez Pérez (1971) indicated that the holotype and paratypes were deposited in DERM, but we have been unable to locate them there (see Notes on Ramírez Pérez’ Simuliidae collection in Materials and Methods).

The previous taxonomic treatment of S. oviedoi also applies to S. rivasi . We have studied the original description of S. rivasi and compared it with link-reared material collected in Venezuela (Material Examined). We conclude that the general morphology, especially female and male genitalia, pupal gill configuration ( Fig. 208 ) and larval hypostomium fall within the variation found in species of the tarsatum species-group of the subgenus Hemicnetha (see Hernández & Shelley, 2005) and hence agree with Coscarón & Coscarón-Arias (2007) and place S. rivasi in this subgenus. Simulium rivasi is closely related to S. oviedoi , but is best recognized by the configuration of the pupal gill filaments ( Fig. 208 ) and the morphology of the tubercles in the pupal frontoclypeus and thorax ( Figs. 209, 210 ) [see comparisons under S. oviedoi .]

Figures

PLATE 14. FIGURES 202–216. Pupal gill filaments and frontoclypeus. 202: S. guerreroi (Venezuela); 203: S. guarani holotype; S. acarayense paratype; 205–207: S. oviedoi (Venezuela); 208–210: S. rivasi (Venezuela); 211: Specimen identified as S. clarki by A.J.Shelley (Brazil); 212: S. clavibranchium syntype; 213: S. clavibranchium variation (Brazil); 214: S. mbarigui holotype; 215: Topotype identified as S. nahimi by V.P.Py-Daneil at INPA; 216: S. subnigrum (Brazil). Arrows indicate a variation on the gill filaments apically.