New synonymy to Simulium (Inaequalium) inaequale (Paterson & Shannon, 1927).

Simulium (Inaequalium) inaequale, described as Eusimulium inaequalis (G Paterson & RC Shannon 1927 Rev Inst Bacteriol 4: 737-742), is a moderately anthropophilic species with a broad distribution. It is known from Brazil (from Amapá, Paraíba, and Mato Grosso to Rio Grande do Sul), Paraguay (Alto Paraná and Cordillera), Bolivia (Nor Yungas, La Paz) and Argentina (Jujuy, Salta, Tucumán, and Misiones). The description of Thyrsopelma argentata Enderlein, 1936 (I Sitz Gesell Naturf Freunde Berlin 125:113-130) was based on a single female specimen. Our revision of this holotype, deposited in the Museum für Naturkunde in Berlin, shows the following characters. General color black; scutum black with grayish pollinosity; according to light direction it shows 1+1 weak sub-median gray bands, with decumbent pilosity varying from silver to copper. Pleurae black with silver pollinosity. Abdomen black, tergite II with 1+1 sublateral silver spots, tergites V-VIII showing a waxy shine. Legs with a color pattern similar to that of S. inaequale. Female genitalia are also similar to those of S. inaequale, paraprocts slightly shorter than basal width, distal border rounded and covered with spicules. Sternite VIII with median dark spot and 1+1 lateral spots. Gonapophyses divergent, sub-triangular, with internal border more sclerotized. Arms of genital fork relatively slim. These characters agree with the description and figures for the subgenus Inaequalium given by S Coscarón and P Wygodzinsky (1984 Arq Zool (São Paulo) 31: 37-103). The dissected genitalia have been attached to the holotype pin. Although we do not know the morphology of the basal portion of the cibarium, that could help us to identify this taxon, the observed characters of T. argentanta do not agree with the diagnostic features of the subgenus Thyrsopelma (type species Simulium orbitale Lutz, 1910 = Thrysopelma brasiliensis Enderlein, 1934) nor with those of Trichodagmia (type species Simulium chalcocoma Knab, 1914 = Trichodagmia latitarsis Enderlein, 1934) based on the actual concept of these subgenera given by RW Crosskey and TM Howard [1997 A New Taxonomic and Geographical Inventory of World Blackflies (Diptera:Simuliidae), The Natural History Museum, London, 144 pp.] Therefore we consider that this holotype specimen of T. argentata belongs to the subgenus Inaequalium. For an accurate species identification additional specimens (females and pupae) need to be examinated, but given the similarity of T. argentata with the description of S. (I.) inaequale and its origin (Bolivia = High Perú = “hoch Peru”), a place where S. (I.) inaequale also occurs (Nigrilluni, Nor Yungas, Dto. La Paz), we propose this new synonymy Simulium (Inaequalium) inaequale (Paterson y Shannon, 1927) = Thyrsopelma argentata Enderlein, 1936. The actual nomenclatural status of S. (I.) inaequale is as follows: Simulium inaequale (Paterson & Shannon, 1927) = Simulium baiense Pinto, 1932 Trichodagmia manicata Enderlein, 1934 Simulium jundiaiense d’ Andretta & Dolores González, 1964 Thyrsopelma argentata Enderlein, 1934.