Simulium (Hemicnetha) oviedoi 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 : 10-11

Simulium (Hemicnetha) oviedoi Ramírez Pérez, 1971

( Fig. 205–207 )

Simulium oviedoi Ramírez Pérez, 1971: 363 . HOLOTYPE [Life stage not indicated in original description.], VENEZUELA: Mérida State, Nacimiento del Rio Motatán , entre el Páramo El Aguila y Chachopo, at 3330 m; [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 oviedoi was described by Ramírez Pérez in 1971 from specimens collected in Venezuela. He did not state which life stage he had designated as the holotype, although he figured and described the female and provided illustrations of the male genitalia, pupal gill filaments, pupal cephalic and thoracic trichomes and larval head capsule and hypostomium. In the original description Ramírez Pérez (1971) stated that the holotype and paratypes were deposited in DERM, but we have been unable to obtain this material for study [see Note on Ramírez Pérez’ Simuliidae collection in Materials and Methods] .

Coscarón (1987) included S. oviedoi together with S. rivasi in the oviedo i species-group, which he regarded as equivalent to a subgenus very close to Hemicnetha and Grenieriella based on the general aspect of adults and the larva. However, he stated that the morphology of the genitalia of the oviedoi- group was similar to Ectemnaspis and related groups. In this paper, he emphasized that the larval morphology precludes the placing of these two taxa in any known subgenus. This was based on the type of the cephalic fan, the presence of robust marginal teeth on the mandible and an intermediate number of rows of hooks in the anal ring [= posterior circlet]. In a later paper Crosskey (1988) recorded both species as “unplaced to species group” within Simulium . However, Peterson et al. (1988) included S. oviedoi and S. rivasi in their key to the New World species of Hemicnetha . This action was not followed in the latest “World Inventory of Simuliidae ” by Crosskey & Howard (2004), where S. oviedoi and S. rivasi were regarded as “Species unplaced to subgenus”. to subgenus. More recently, Coscarón & Coscarón-Arias (2007) placed S. oviedoi and S. rivasi in the oviedoi group in the subgenus Hemicnetha .

We have studied the original description and illustrations of S. oviedoi in Ramírez Pérez (1971, 1983) and compared these with material collected in Venezuela deposited in the AMNH (Material Examined). The general morphology of the female and male genitalia, pupal frontoclypeus and gill configuration ( Figs. 211, 212 ), wing venation and larval hypostomium fall within the variation found in species of Hemicnetha . Therefore, we agree with Coscarón & Coscarón-Arias (2007) and place S. oviedoi in this subgenus and subsume this group in the tarsatum -species group (sensu Hernández & Shelley, 2005).

The adults of S. oviedoi are very difficult to identify without examination of the pupal gill. The pupal gill in S. oviedoi has six filaments, which easily separates it from other species of Hemicnetha , except S. cristalinum and S. rivasi . Simulium oviedoi is most closely similar to S. rivasi because all primary branches arise from a short and wide common trunk ( Figs. 205, 208 ), but they can be separated by the morphology of the tubercles on the frontoclypeus and thorax of the pupa. In S. oviedoi the frontoclypeus and the thorax of the pupa are densely covered by distinct spiny tubercles ( Fig. 206–207 ), whereas in S. rivasi they are densely covered with rounded tubercles ( Fig. 209–210 ). Simulium cristalinum can be recognized by the dorsal set of primary branches dividing at some distance from the base of the gill, and the frontoclypeus and the thorax of the pupa with sparsely distributed, rounded tubercles (see Coscarón & Py-Daniel, 1989).

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.