Simulium (Hemicnetha) tarsatum Macquart

Hernández, L. M. & Shelley, A. J., 2005, New specific synonymies and taxonomic notes on Neotropical blackflies (Diptera: Simuliidae), Zootaxa 853, pp. 1-46 : 6-9

Simulium (Hemicnetha) tarsatum Macquart

(Figs. 7–14, 39–41, 53–55, 67–69, 81, 82)

Simulium tarsatum Macquart, 1846 [1844]: 20. HOLOTYPE Ψ [Not ɗ as published.], COLOM­ BIA (as “ Nouvelle­Grenade ” in description, “Nova Granata” on label) [Handwritten label, S. tarsatum , n.sp.] [Collection date and collector unknown.] (BMNH, ex. Bigot Collection, B.M. 1960–1539). [Examined.]

Simulium mexicanum Bellardi, 1862 (appendix to part 2): 6. LECTOTYPE Ψ, MEXICO: Veracruz State, Tuxpango, near Orizaba; [Collection date and collector unknown.] (DBAT). [Examined.] [Lectotype designation in Shelley et al., 1989: 103.] New synonymy.

Simulium seriatum Knab, 1914: 84 –85. HOLOTYPE Ψ, PERU: Sta Eulalia, 12091; 5.vii.1913, (C.H.T.Townsend) (USNM, type no. 18349) [Examined.] New synonymy.

Simulium aureopunctatum Malloch, 1914: 27 . HOLOTYPE Ψ. GUATEMALA: Livingston; 6.v. or 5.vi. [Year not given.], (Barber & Schwarz) (USNM, cat. no. 15406) [Examined.] [Previous synonymy with mexicanum by Bequaert 1934: 208.] New synonymy.

Simulium placidum Knab, 1915: 281 . HOLOTYPE Ψ, TRINIDAD: Arima river; 31.xii.1913, (F.W.U r i c h) (BMNH) [Examined.] [Previous synonymy with mexicanum by Vargas & Díaz Nájera, 1951: 133.] New synonymy.

Simulium lugubre Lutz & Nuñez Továr in Lutz, 1928: 46 . SYNTYPES Ψ ɗ, VENEZUELA: Aragua, Rio de Maracay, La Trinidad; 28.xii.1915, (A.Lutz & Nuñez Továr) (IOC). [Examined.] [Previous synonymy with mexicanum by Fairchild, 1940: 708.] New synonymy.

Simulium turgidum Hoffmann, 1930: 298 . SYNTYPES ΨΨ, MEXICO: Chiapas State, Soconusco District, Finca Santa Anita; vii.1930, [Collector and depository unknown.] [Previous synonymy with mexicanum by Bequaert, 1934: 208.] New synonymy.

Trichodagmia laticalx Enderlein, 1934a: 291 –292. LECTOTYPE Ψ, PERU: Challanga; [Without date or collector.] (NMHU) [Examined.] [Previous synonymy with S. seriatum by Coscarón, 1987: 36.] New synonymy. New type designation.

Trichodagmia latidigitus Enderlein, 1936: 129 . LECTOTYPE Ψ, COLOMBIA: Muzo terr. aol; [Without date.], ( O.Thieme S.) (NMHU) [Examined.] [Previous synonymy with S. seriatum by Coscarón, 1987: 36.] New synonymy. New type designation.

Simulium bellardii Py­Daniel & Moreira Sampaio, 1994: 149 . [Unnecessary replacement name for mexicanum Bellardi proposed by these authors on upgrading the subgenus Hemicnetha to genus – see Crosskey & Howard, 1997: 85.] New synonymy.

The name S. tarsatum was given by Macquart (1846) to a single female collected in Colombia (as Nouvelle­Grenade), but published as “ɗ”. This situation is recorded in Townsend et al. (1990). It is similar to Macquart’s description of female types of S. nigrimanum as males [see Shelley et al. (1984)]. We have examined this specimen, which is housed in the BMNH, and the most pertinent label details are as follows: an original label “Nova Granata. Macq. nomin. D. Exot.” and a smaller label stuck on to this in Macquart’s hand “ Simulium tarsatum n.sp.”; a label with Simulium tarsatum Macq. COLOMBIA ex. Bigot Coll: B.M. 1960­539 [recording the donation from M. Bigot’s collection where Macquart deposited the holotype]; a label in Crosskey’s hand “ HOLOTYPE Ψ (not ɗ as published in Macquart) Simulium tarsatum Macquart det. R.W.Crosskey, 1979”. Details of the other more recent labels are given in “ Material Examined ”. The specimen is in poor condition with the head, left wing, and all legs missing. It has been pinned through the central region of the thorax, which has badly damaged the scutum and scutellum (Figs. 7, 8). However, the rest of the thorax shows the adpressed, brass coloured setae in groups, which is typical of S. mexicanum [see Shelley et al., 2002] and the genitalia are also the same (Figs. 53, 67, 81). Therefore, we regard S. mexicanum and S. tarsatum as synonymous, with the name S. tarsatum having priority over S. mexicanum (International Code of Zoological Nomenclature, 1999). A full description of all life stages of S. tarsatum (as S. mexicanum ) may be found in Shelley et al. (1989, 2002). Shelley et al. (2002) detailed all diagnostic characters of S. mexicanum , examined type material, discussed synonyms, type depositories, and its biology and distribution. We have examined all this material and continue to support all the synonyms listed under S. mexicanum . Since then, we have examined type material of most Neotropical species described by Enderlein in 1934 and 1936 and based on this the following are regarded as synonyms of S. tarsatum .

Simulium seriatum was briefly described by Knab (1914) based on two females collected in Santa Eulalia and Chosica, Peru, by C.H.T. Townsend in July and September 1913. Since its original description S. seriatum had remained poorly known until Coscarón & Coscarón­Arias (2000) fully redescribed all life stages based on material collected from Argentina, Bolivia, Ecuador, Peru, and Venezuela. They were only able to reliably distinguish S. seriatum from S. mexicanum by the length of the sensorial organ of the maxillary palp, the density of thoracic tubercles (as platelets) on the pupa and frontoclypeus, and the thickness of the cocoon. Coscarón­Arias (2003) also used the last two characters to separate S. seriatum from S. mexicanum in her key to the Simuliidae of Ecuador. Coscarón & Coscarón­Arias (2000) stated that in S. seriatum the platelets were scarcer, leaving smooth areas on the thorax and frontoclypeus; the sensorial lobe measured 1.6–2.9 mm (mean = 2.1 mm, n = 10). In S. mexicanum they found that the platelets were more abundant, completely covering the exposed areas of the thorax and frontoclypeus, the sensorial lobe measured 2.9–3.3 mm (mean = 3.1 mm, n = 6), and the cocoon was thicker and more reinforced anteriorly, thus obscuring most of the pupa. We have studied these descriptions and illustrations and compared material identified by Coscarón as S. seriatum in the USNM and AMNH (see “ Material Examined ”) with large series of reared specimens identified as S. mexicanum in the BMNH. We found morphological variations in the density of tubercles on the frontoclypeus and pupal thorax and in the structure of the cocoon on specimens of S. tarsatum (as S. mexicanum ) that we had collected from Belize in Central America ( Shelley et al., 2002) and in material from Ecuador deposited in the BMNH. Also, from our experience with several Neotropical species, the sensory organ of the maxillary palp can vary intraspecifically. We have examined the holotype, paratype, and a female topotype of S. seriatum in the USNM. The head, abdomen, genitalia, wing, and legs of these specimens have been dissected and are mounted on three slides. No differences were found between these specimens (Figs. 9, 10, 39, 54, 68, 82), material previously regarded as S. mexicanum and the holotype of S. tarsatum . Consequently, we regard all the material identified as S. seriatum by Coscarón & Coscarón­Arias (2000) and Coscarón­Arias (2003) as conspecific with S. mexicanum , itself now a synonym of S. tarsatum .

Two species have been treated by Coscarón (1987) as synonyms [without explanation] of S. seriatum : T. laticalx and T. latidigitus . These names were also included in the list of synonyms with S. seriatum in a paper in which this species was redescribed ( Coscarón & Coscarón­Arias, 2000). Trichodagmia laticalx was described by Enderlein (1934a) from two syntype females collected in Callanga and Rosalina (Urubamba) and said to be deposited in the NMHU and SMT, respectively. We have only been able to find the specimen in the NMHU, which has been recorded as a syntype by Werner (1996a). We designate this specimen as the lectotype and have labelled it accordingly. The other specimen in the SMT has been lost (Uwe Kallmeit, pers. comm.). Our examination of the lectotype revealed that it was in poor condition and lacking genitalia. Vargas & Díaz Nájera (1953) had previously recorded that they were unable to observe the genitalia “due to mutilation by psocids “polilla” and that it appeared close to S. mexicanum . The thorax and three legs of the lectotype were left pinned (Figs. 11, 12) and the head, wings, and the other three legs have been dissected and mounted on a slide (Fig.40). Coscarón’s synonymy (1987) of this species with S. seriatum , which he regarded as closely related to S. mexicanum ( Coscarón & Coscarón­Arias, 2000; Coscarón­Arias, 2003), causes no taxonomic problem because both names are now junior synonyms of S. tarsatum . In 1936, Enderlein described T. latidigitus based on two syntype females collected in Muzo, Colombia. In a paper reviewing the Enderlein types at NMHU Werner (1996a) stated that a “female lectotype, and a female paralectotype bearing the same locality data as the lectotype are deposited in the NMHU collection”. This was based on “all details from the literature in comparison with the collection” (D. Werner, pers. comm.). We have examined this material but found no labels on the specimens referring to lectotype and paralectotype. Also, we are unaware of any reference in the Neotropical Simuliidae literature designating a lectotype for this species. Paradoxically, the specimen in better condition bears an orange “ Paratypus ” label and the other specimen [recorded as lectotype] an orange “ Typus ” label. The person that selected the typus and paratypus specimens and labelled the specimens with these orange labels is not known (D. Werner, J. Ziegler, pers. comm.). Since both specimens bear a label in Enderlein’s hand with “ Type ” [see “ Material Examined ”] we consider both specimens as syntypes. We have selected the specimen that is in better condition and bears a handwritten label by Coscarón “ Simulium (Hemicnetha) seriatum det. 85” as lectotype and have labelled it accordingly. The other specimen, which has been pinned through the thorax and is in poor condition due to greasing, has been designated and labelled as paralectotype. Both specimens have been dissected and the head, genitalia, left wing and legs (only one mid and hind leg of the lectotype) are mounted on two slides. The thorax, the right wing of each of the two specimens, and the three legs of the lectotype remain pinned. We have studied the scutal pattern (Figs. 13, 14) and the morphology of the cibarium (Fig. 41), genitalia (Figs. 55, 69, 83), and wing setation and the leg coloration of S. latidigitus and accept that this species falls within the morphological variation found in S. tarsatum and hence is its junior synonym.

Crosskey & Howard (1997; 2004) regarded S. tarsatum as “ Simulium sensu lato, species unplaced to subgenus” in their World Inventory of Blackflies. The morphology of the genitalia of S. tarsatum falls within the variation found in species of the subgenus Hemicnetha . With the synonymy of S. mexicanum with S. tarsatum , the mexicanum species group of Adler et al. (2004), Coscarón (1987, as sub­group), and Crosskey & Howard (2004) now becomes the tarsatum species group.