Simulium (Chirostilbia) spinibranchium Lutz

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 : 6-8

Simulium (Chirostilbia) spinibranchium Lutz

( Figs. 1–4 , 79, 92 , 98 , 115–120 )

Simulium spinibranchium Lutz, 1910: 248 [as S. subpallidum ], 261 [as S. spinibranchium (= subpallidum ?)]. LECTOTYPE pharate ♂ & pupal exuviae, BRAZIL: São Paulo State, Anhemby [now Anhembí]; [Without date.], (A. Lutz) (IOC, no. “12.337, Bd. 188”, and “181”). [Examined.] [Lectotype designation by Py-Daniel & Shelley 1980: 218.]

Thyrsopelma striginotum Enderlein, 1934a: 284 . HOLOTYPE ♀, BOLIVIA: Mapiri , Sarampioni, 700 m; 14.ii.1903 [Without collector’s name.] (SMT) [Examined.] New synonymy.

Simulium laneportoi Vargas, 1941: 118 . HOLOTYPE ♀, BRAZIL: Mato Grosso State, Ponte Alta, viii.1934, (S.F.A.) (MZUSP) [New name for S. pillosum Porto, 1940: 383 and S. pilosum Lane & Porto, 1940: 190 (nec Eusimulium pilosum Knowlton & Rowe, 1934: 580 ) by Vargas, 1941: 118.] [Examined.] [ Simulium dekeyseri synonymized with S. laneportoi by Py-Daniel, 1987: 331, but S. dekeyseri resurrected from this synonymy in this paper.] New synonymy.

Simulium spinibranchium was described and figured by Lutz (1910) from pupae collected at Anhemby [=Anhembí] on the River Tiete (São Paulo) and Lassance (Minas Gerais), Brazil. The taxonomic confusion regarding this species has been reviewed under S. subpallidum . Py-Daniel & Shelley (1980) described the adults and larvae for the first time and designated a pharate male from Anhembí as a lectotype, which is housed in the IOC. The pharate male and its corresponding pupal exuviae are mounted on a slide. This slide was re-mounted in Berlese medium in 2002 by Amaral-Calvão (see Amaral et al., 2006). The slide has dried out and it contains one wing, three legs and both pupal gill filaments, which have all filaments broken [For label details see Material Examined].

Enderlein (1934a) described Thyrsopelma striginotum from a single female collected at Mapiri in Bolivia. We have examined the female holotype, which is housed in the SMT. The genitalia of the holotype, along with the third and fourth tarsal segments of one leg are mounted on a small slide glued to a card. The front leg has also been glued to a card and attached to the pinned adult. The antenna, right wing and hind legs are missing. The specimen bears two hand-written labels in Enderlein’s hand and one identification label by Coscarón [see Material Examined] .

We have taken digital images of the thorax prior to dissection of the head, the mid legs and the left wing, which are now mounted on a slide. The thorax remains pinned. By comparison largely with digital images archives in the BMNH, and with specimens of Chirostilbia species in the BMNH, MLP and IOC collections, the female thoracic pattern of S. striginotum was seen to be similar not only to S. spinibranchium , but also to other species such as S. dekeyseri and S. jefersoni in that the thorax is black with 1+1 median and 1+1 submedian silver pruinose bands extending from the anterior to the posterior margins of the thorax [light source anterior] ( Figs. 1–2 ). However, the general morphology of the head (nudiocular area and cibarium) ( Figs. 79 , 97 ), wing setation, leg coloration, and the structure of the genitalia, especially the cercus and paraproct ( Figs. 115–117 ) fall within the variation found in S. spinibranchium . Therefore, we consider S. striginotum as a junior synonym of S. spinibranchium . The apparent presence of an anterior process on the left side of the genital fork of S. striginotum ( Fig. 117 ) is due to an artifact caused during slide preparation when a piece of chitin became superimposed on the broken left lateral arm. Although the right arm is broken it is still intact and shows the true form of this part of the genital fork. Coscarón (1987) regarded S. striginotum as a species inquirenda within the subgenus Thyrsopelma . It was placed in the subgenus Chirostilbi a by Crosskey & Howard (2004), an action with which we concur.

A further species here considered as a junior synonym of S. spinibranchium is S. laneportoi Vargas (as S. pillosum Lane & Porto ). Porto (1940) [actual date of publication 27.vi.1940] re-described two species of Simuliidae , S. exiguum and S. subnigrum , from material sent to him by S.F.A. from Restrepo, Colombia. In this paper he also included a key to separate other simuliid species and introduced the name S. pillosum . He referred to and keyed out “ S. pillosum Lane & Porto ” as a species with “…dense, silver tomentum and thorax without a white lateral band…”. Following the rules of the ICZN (1999) this constitutes the original description and the valid name of the species. In a paper published in the same year, Lane & Porto (1940) [actual date of publication 31.xii.1940] provided a full description of S. pilosum [note now the spelling with a single “l”, see pages 190–192] from a pinned female holotype and six female paratypes (one on a slide) collected on human bait in the states of Mato Grosso (Chapada, Ponce) and Paraná (Cambará). Both S. pillosum [double “ll”] and S. pilosum [single “l”] refer to the same species. We believe the name S. pilosum in Lane & Porto (1940) might be a typographical error because the specimens bear original labels with the name S. pillosum written with a double “ll” (see Material Examined). In a previous publication, Knowlton & Rowe (1934) in their study of simuliids from Utah described five species in the genus Eusimulium , and named one of them E. pilosum . As Eusimulium is considered a subgenus of Simulium , the name S. pilosum constituted a junior primary homonym of E. pilosum ( ICZN 1999, article 58) and so Vargas (1941) proposed the name S. laneportoi (as S. lane-portoi ) for the species from Brazil. In the same paper, Vargas (1941) mistakenly attributed the origin of the specimens of S. pillosum Lane & Porto to Restrepo, Colombia. A subsequent misspelling of the latter name as S. lane-porteroi was made by Smart (1945) in his classification of the Simuliidae of the world. We have examined the female holotype and one female paratype of S. laneportoi , which are housed in the MZUSP. Both specimens are in good condition, and digital images have been taken of them before dissecting the abdomen of the holotype, which is now mounted on a slide. The head of the holotype had been previously dissected by an unknown reviser and is on a small cover slip, glued to a card that is attached to the pin. The thorax, legs and wings of the specimen remain pinned. A label stating that this specimen represents the holotype of S. laneportoi has been attached to it.

Simulium dekeyseri Shelley & Py-Daniel (1981) was synonymized with S. laneportoi by Py-Daniel (1987), who also provided further information on the type locality of S. laneportoi . However, after examination of the type material we have the following comments to make. Simulium dekeyseri was described by Shelley & Py-Daniel (1981) from a series of females, males, larvae and pupae collected in the state of Goiás and in the Federal District of Brasília, Brazil. The holotype is deposited in the IOC. The pinned female holotype has been glued to a card point together with its pupal exuviae. The specimen has only the thorax, right wing, and parts of the legs of the left side; the remaining body parts are missing (see Material Examined). In 1987 Py-Daniel stated that he had studied the type and topotype reared material of S. laneportoi Vargas and S. dekeyseri and regarded S. dekeyseri as a junior synonym of S. laneportoi . We have studied the thoracic pattern of the holotype ( Figs. 3, 4 ) [see also thoracic pattern of a paratype Figs. 5, 6 ], the nudiocular area ( Fig. 80 ), cibarium ( Fig. 98 ), wing venation, leg coloration and genitalia ( Figs. 118–120 ) of the female holotype of S. laneportoi and compared it with the thoracic pattern ( Figs. 7, 8 ), and general morphology of the female holotype and paratypes ( Figs. 81 , 99 , 121–123 ) and numerous linked-reared specimens of S. dekeyseri and found that they are not conspecific. The female thoracic pattern of S. laneportoi is similar to other species of Chirostilbia such as S. dekeyseri , S. jefersoni , and S. spinibranchium in that it is black with 1+1 median and 1+1 sub-median silver pruinose vittae extending from the anterior to posterior margins [light source anterior] ( Figs. 3, 5, 7 ; BMNH image archives). However, S. laneportoi can be distinguished from the other species especially by the morphology of the paraproct ( Fig. 118 ), which falls within the variation found in S. spinibranchium (see Shelley et al., 2004) and so we place S. laneportoi as its junior synonym. We believe that the slightly different morphology of the cercus and paraproct of S. laneportoi compared to the genitalia of S. striginotum ( Fig. 115 ) and other link-reared females identified as S. spinibranchium housed in the BMNH is due to the positioning of this structure on the slide preparation. The paraproct in S. dekeyseri differs in that it is narrower centrally and also becomes narrower towards its apex ( Fig. 121 ). Therefore, we regard S. dekeyseri as a valid species within the subgenus Chirostilbia . The female of S. jefersoni is distinguished by its smaller, sub-triangular paraproct, which is nearly 1.5 times the length of cercus (Hamada et al., 2005). Simulium dekeyseri can be further distinguished by the truncate gonostyle of males, which is half the length of the gonocoxite and the sub-triangular ventral plate prominently developed in the central region (see Shelley & Py-Daniel, 1981).

Simulium spinibranchium is best recognized by the antler-like configuration of the pupal gill filaments ( Shelley et al. 2000). The females can be identified based on the long, sub-triangular paraproct, which is wide centrally and the structure of the male gonostyle (see Shelley et al. 2000; 2004). This species has limited distribution in the highland areas of north-eastern Roraima State in Brazil and in southern Venezuela, where it bites man voraciously. In other areas of Brazil this species in totally zoophilic (A.J.Shelley & A.P.A. Luna Dias, unpublished data). In Brazil it has only been collected in the states of São Paulo, Bahía, Federal District, Goiás, Mato Grosso, Minas Gerais, Rio de Janeiro, Roraima ( Crosskey & Howard, 2004) and Rio Grande do Sul (Strieder, 1992). Elsewhere it occurs in Bolivia [as S. striginotum ], Guyana and Venezuela ( Shelley et al., 2004; this study).

Figures

PLATE 1. FIGURES 1–16. Colour patterns of the female thorax. For each species first figure is with anterior illumination and second figure with posterior illumination. 1, 2: Thyrsopelma striginotum holotype; 3, 4: S. pillosum holotype; 5, 6: S. pillosum paratype; 7, 8: S. dekeyseri holotype; 9, 10: S. guarani holotype; 11, 12: S. acarayense holotype; 13, 14: S. mutucuna holotype; 15, 16: S. inaequale neotype.

PLATE 6. FIGURES 79–96. Female nudiocular area. 79: Thyrsopelma striginotum holotype; 80: S. pillosum holotype; 81: S. dekeyseri paratype; 82: S. acarayense paratype; 83: Trichodagmia manicata lectotype; 84: Thyrsopelma argentata holotype; 85: S. clarki paratype; 86: S. subnigrum (Brazil); 87: Psaroniocompsa opalinifrons holotype; 88: S. jujuyense (Argentina); 89: S. auripellitum holotype; 90: Pliodasina guttata holotype; 91: S. bonaerense paratype; 92: S. minuanum paratype; 93: S. costaricensis holotye; 94: S. spinifer holotype; 95: S. hoffmani lectotype; 96: S. sicuani lectotype.

PLATE 7. FIGURES 97–114. Female cibarium. 97: Thyrsopelma striginotum holotype; 98: S. pillosum holotype; 99: S. dekeyseri paratype; 100: S. acarayense paratype; 101: Trichodagmia manicata lectotype; 102: Thyrsopelma argentata holotype; 103: S. clarki paratype; 104: S. subnigrum (Brazil); 105: Psaroniocompsa opalinifrons holotype; 106: S. jujuyense (Argentina); 107: S. auripellitum holotype; 108: Pliodasina guttata holotype; 109: S. bonaerense paratype; 110: S. minuanum paratype; 111: S. costaricensis holotye; 112: S. spinifer holotype; 113: S. hoffmani lectotype; 114: S. sicuani lectotype.

PLATE 8. FIGURES 115–126. Female genitalia (cercus and pararprocts, eighth sternite and gonopophyses). 115–117: Thyrsopelma striginotum holotype; 118–120: S. laneportoi holotype; 121–123: S. dekeyseri paratype; 124–126: S. acarayense paratype. Arrow indicate a piece of chitin (artefact) superimposed on the broken left lateral arm.