Simulium (Inaequalium) margaritatum Pepinelli, Hamada & Luz

Pepinelli, Mateus, Hamada, Neusa & Luz, Sérgio Luiz Bessa, 2006, Simulium (Inaequalium) margaritatum, a new species of black fly (Diptera: Simuliidae) from the central region of Bahia State, Brazil, Zootaxa 1167 (1), pp. 47-60: 48-59

publication ID

http://doi.org/ 10.11646/zootaxa.1167.1.4

publication LSID

lsid:zoobank.org:pub:012C83BC-8E6F-412A-B66E-35A498BC62E0

persistent identifier

http://treatment.plazi.org/id/A77787B4-FFD5-3D7A-FEEE-FB17FDB665B4

treatment provided by

Felipe

scientific name

Simulium (Inaequalium) margaritatum Pepinelli, Hamada & Luz
status

 

Simulium (Inaequalium) margaritatum Pepinelli, Hamada & Luz  

( Figs. 1–42 View FIGURES 1–2 View FIGURES 3–13 View FIGURES 14–22 View FIGURES 23–26 View FIGURES 27–32 View FIGURE 33 View FIGURE 34 View FIGURES 35–42 )

Description

FEMALE ( Figs. 1–13 View FIGURES 1–2 View FIGURES 3–13 ). General body color dark brown to black ( Figs. 1, 2 View FIGURES 1–2 ). Body length 1.8–2.2 mm (n = 2); thorax lateral length 0.8 mm (n = 2); thorax dorsal length 0.8–0.9 mm (n = 2). Wing length 2.0 mm (n = 2); wing width 0.6–0.7 mm (n = 2).

Fronto­ocular triangle well developed ( Fig. 7 View FIGURES 3–13 ). Frons, clypeus, and occiput black, with silver pruinosity. Antenna with silver pubescence, 0.37–0.39 mm (n = 4) in length; scape and pedicel light brown, remaining segments dark brown ( Fig. 5 View FIGURES 3–13 ). Maxillary palpus dark brown; sensory vesicle elongated occupying more than 1/3 of length of palpomere III; palpomere V twice length of palpomeres III and IV ( Fig. 9 View FIGURES 3–13 ). Mandible with 10 external serrations and 29–31 internal teeth. Lacinia with 26 or 27 retorse teeth. Cibarium with well developed, sclerotized cornuae, with teeth arranged over median elevation ( Fig. 3 View FIGURES 3–13 ) [in 5 specimens we examined, 1 did not have central elevation ( Fig. 4 View FIGURES 3–13 )]. Thorax with scutum black covered by evenly arranged, recumbent, golden greenish hairs (and some reddish hairs), without pattern ( Fig. 1 View FIGURES 1–2 ). Anepisternum and katepisternum dark brown with silver pruinosity. Scutellum dark brown with long dark setae and few golden setae. Postnotum with silver pruinosity. Costa of wing with spines and setae ( Fig. 6 View FIGURES 3–13 ). Subcosta with sparse distribution of setae ( Fig. 6 View FIGURES 3–13 ). Basal section of radius bare; R1 with spines and setae; Rs with setae. Leg coloration as in male, except hind leg with basitarsus proximal 2/3 whitish and distal 1/3 dark brown. Claws curved, with basal tooth ( Fig. 8 View FIGURES 3–13 ). Abdominal tergite II with silver pruinosity on anterolateral margins ( Fig. 2 View FIGURES 1–2 ). Tergite plates II–IX with varnishlike appearance. Basal fringe with long, golden hairs. Sternites grayish brown; genitalia dark brown. Eighth sternite weakly sclerotized with evenly distributed setae; hypogynial valves (= gonapophyses) subtriangular, without microtrichia and membranous, except weakly sclerotized on internal margins ( Fig. 13 View FIGURES 3–13 ). Cercus rounded, covered with small hairs and long brown setae; anal lobe (= paraproct) short, with small protuberance near cercus ( Fig. 12 View FIGURES 3–13 ). Genital fork stout, sclerotized with distal end of stem weakly expanded; lateral arms well developed, with large anterior process; lateral arms forming suboval space ( Fig. 10 View FIGURES 3–13 ). Spermatheca globular, with internal spicules arranged in groups ( Fig. 11 View FIGURES 3–13 ); spermathecal duct unpigmented.

MALE ( Figs. 14–26 View FIGURES 14–22 View FIGURES 23–26 ). General body color dark brown ( Figs. 14–16 View FIGURES 14–22 ). Body length 2.2 mm (n = 1); thorax lateral length 0.83 mm (n = 1); thorax dorsal length 0.78 mm (n = 1). Wing length 1.8 mm (n = 1); wing width 1.3 mm (n = 1).

Antennae with silver pubescence, 0.42–0.47 mm (n = 4) in length; scape and pedicel brown, remaining segments dark brown. Palpus dark brown, sensory vesicle small, occupying less than 1/5 of palpomere III; palpomere V about 2.3 times as long as palpomeres III and IV ( Fig. 19 View FIGURES 14–22 ). Scutum black covered with golden hairs. Scutal pattern varies with light incidence: with anterior light source, scutum black with 1 + 1 anterolateral rounded, well­defined silver spot ( Fig. 14 View FIGURES 14–22 ); with posterior light source, scutum black ( Fig. 15 View FIGURES 14–22 ). Lateral and posterior margins of scutum pruinose ( Fig. 16 View FIGURES 14–22 ). Scutellum dark brown with long, black hairs and short, sparse, golden hairs. Postnotum with silver pruinosity. Anepisternum and katepisternum dark brown with silver pruinosity. Costa of wing with spines and setae ( Fig. 18 View FIGURES 14–22 ). Subcosta bare ( Fig. 18 View FIGURES 14–22 ). Basal section of radius bare ( Fig. 18 View FIGURES 14–22 ); R1 with spines; Rs with setae. Leg coloration and proportions as in Figs. 20, 21 View FIGURES 14–22 . Fore leg with coxa, trochanter, and femur dark brown, tibiae with anterior region whitish and posterior brown, basitarsus and tarsomeres I–IV dark brown ( Fig. 20 View FIGURES 14–22 ). Middle leg with coxa, trochanter, and femur dark brown, proximal 1/3 of tibia whitish and distal 2/3 dark brown, more than half of proximal region of basitarsus whitish, remaining dark brown and tarsomeres I–IV dark brown ( Fig. 21 View FIGURES 14–22 ). Hind leg with coxa, trochanter, and femur dark brown, proximal 2/3 of tibia dark brown and distal 1/3 whitish, proximal 3/4 of basitarsus whitish and distal 1/4 dark brown, tarsomeres I–IV dark brown ( Fig. 22 View FIGURES 14–22 ). Claws without basal tooth, but with well­developed thumblike lobe ( Fig. 17 View FIGURES 14–22 ). Calcipala reaching pedisulcus. Femur and tibia of middle and hind leg with scalelike setae distributed among filiform ones. Abdominal tergites ( Fig. 16 View FIGURES 14–22 ) black; basal fringe with long, thin, blackgolden hairs; tergite II black with silver pruinosity; tergite III without silver pruinosity; tergites IV–VII with silver pruinosity on laterodorsal edge. Abdominal sternites membranous. Sternites III–VIII with silver pruinosity on median region. Genitalia dark brown; gonocoxite and gonostylus covered with small hairs and long setae; gonocoxite subquadrangular ( Fig. 23 View FIGURES 23–26 ); gonostylus subtrapezoidal ( Fig. 23 View FIGURES 23–26 ), nearly as long as gonocoxite at mid point, with 1 subterminal spine. Ventral plate elongated, covered by long hairs, as in Fig. 26 View FIGURES 23–26 . Median sclerite Y shaped ( Fig. 25 View FIGURES 23–26 ). Paramere with developed and sclerotized basal process and numerous stout teeth ( Fig. 24 View FIGURES 23–26 ).

PUPA ( Figs. 27–34 View FIGURES 27–32 View FIGURE 33 View FIGURE 34 ). Cocoon length dorsally 2.4–2.7 mm (mean = 2.5 mm, SD = 0.13, n = 5), ventrally 3.0– 3.3 mm (mean = 3.1 mm, SD = 0.15, n = 5); pupa lateral length 2.1–2.6 mm (mean = 2.3 mm; SD = 0.22, n = 5).

Cocoon slipper shaped, light brown, composed of thick coalesced fibers with short dorsal projection ( Figs. 27, 30 View FIGURES 27–32 ). Cephalic plate with 2 + 2 long, bifid or trifid frontal and 1 + 1 bifid dorsal trichomes; tubercles rounded, densely distributed over entire cephalic plate ( Figs. 29, 32 View FIGURES 27–32 ). Thorax with 5 pairs of long trichomes, each with 3–8 ramifications ( Fig. 28 View FIGURES 27–32 ), near edge of dorsal cleft; tubercles rounded, sometimes acuminated, densely distributed over entire surface; on anterior region, tubercles bigger than on posterior region. Gill length 3.2–3.7 mm (mean = 3.4 mm, SD = 0.22, n = 5) pale brownish. Gill with 4 forwardly directed filaments, with main trunk short, giving rise to 2 short sets of primary branches that bifurcate near gill base into 2 secondary branches each consisting of 2 filaments ( Fig. 31 View FIGURES 27–32 ). All gill filaments approximately same length ( Fig. 27 View FIGURES 27–32 ), with rounded ends ( Fig. 31 View FIGURES 27–32 ). Abdominal tergites as in Figs. 33a–d View FIGURE 33 . Tergite I with 1 + 1 filiform setae and 2 + 2 submedian short, strong setae. Tergite II with 3 + 3 submedian simple or bifid trichomes and 3 + 3 short setae on lateral region near external trichome ( Fig. 33a View FIGURE 33 ). Tergites III–IV with 4 + 4 submedian simple or bifid hooks ( Fig. 33b View FIGURE 33 ). Tergites V–IX with spine combs on anterior edge ( Figs. 33c–d View FIGURE 33 ). Tergites II–IX with 1–5 submedian simple trichomes and 1–3 simple trichomes on lateral margin; tergite IX weakly sclerotized. Abdominal sternites as in Figs. 34a–c View FIGURE 34 . Sternites III–IV with spine combs on anterior edge. Sternite V with 2 + 2 close, bifid hooks in row and 2 + 2 simple trichomes on lateral margin ( Fig. 34a View FIGURE 34 ). Sternite VI–VII with 2 + 2 simple or bifid hooks and 2 + 2 simple, small trichomes near hooks ( Fig. 34b View FIGURE 34 ). Sternite VIII without hooks. Abdominal sternites III–VIII with spine combs on anterior edge ( Fig. 34c View FIGURE 34 ).

LARVA (last instar) ( Figs. 35–42 View FIGURES 35–42 ). Body length: 4.9–5.3 mm (mean = 5.1 mm, SD = 0.2, n = 5); lateral length of head capsule: 0.64–0.69 mm (mean = 0.66 mm, SD = 0.02, n = 5); dorsal width of head capsule: 0.52–0.56 mm (mean = 0.54 mm, SD = 0.02, n = 5).

General body coloration light to dark gray (in Carnoy’s solution). Head pale to dark brown with positive pattern ( Fig. 35 View FIGURES 35–42 ); cuticle of dorsal and ventral region with small, simple setae. Cervical sclerites small, free in membrane. Postgenal cleft narrow, subtriangular ( Figs. 36, 37 View FIGURES 35–42 ). Postgenal bridge 0.7 times as long as hypostoma ( Fig. 37 View FIGURES 35–42 ). Hypostoma with strongly pigmented anterior edge and 9 apical teeth ( Fig. 39 View FIGURES 35–42 ): median tooth simple and more prominent than sublateral teeth, 3 + 3 rows of sublateral teeth, middle tooth smaller than remaining teeth, 2 poorly developed paralateral teeth, and 6 or 7 small lateral serrations; hypostoma with 1 + 1 line of 5 or 6 lateral setae parallel to lateral edge and 1 + 1 long and 1 + 1 or 2 + 2 short setae in posterior region of hypostoma near hypostomal groove. Subesophageal ganglion pigmented ( Fig. 36 View FIGURES 35–42 ). Antenna as long as labral fan stalk; antennal articles pale brown, except distal article, which is darker than proximal and medial articles ( Fig. 41 View FIGURES 35–42 ); segment proportions (proximal, medial, distal) approximately 0.9–1.0:0.7–0.8:1.3–1.4 (n = 2). Mandible with 3 apical teeth, 10 internal teeth, 1 large mandibular serration, 1 small mandibular sensillum (sensu Craig & Craig 1986) and 1–2 lateral mandibular processes thick and longer than mandible edge ( Fig. 38 View FIGURES 35–42 ). Cephalic fan with 44–48 rays. Thorax gray dorsally and ventrally. Gill histoblast dissected, with 4 filaments. Abdomen usually completely grey dorsally, progressively paler ventrally, posterior region whitish ventrally; faint segmental banding visible dorsally ( Fig. 40 View FIGURES 35–42 ). Ventral nerve cord dark grey. Ventral tubercles small, subtriangular. Anterodorsal arms of anal sclerite shorter in length than posteroventral arms ( Fig. 42 View FIGURES 35–42 ). Posterior proleg bearing approximately 80 rows of up to 12 or 13 hooks (n = 2). Anal papillae with 3 branches, each with approximately 5 or 6 fingerlike lobes of same length (n = 2).

Taxonomic Discussion

Simulium margaritatum   n. sp. is placed in the subgenus Inaequalium   , based on the combination of characters given by Coscarón & Wygodzinsky (1984). This new species might be included in the inaequale   species group because it has males with the gonostylus subtrapezoidal, pupae with filiform gill filaments, larvae with the postgenal cleft narrow and subtriangular, and the postgenal bridge 0.7 times as long as the hypostoma ( Coscarón 1987). However, males of this new species have the ventral plate longer than wide, as in species of the S. botulibranchium   group. According to Coscarón (1987), the females of the species in the subgenus Inaequalium   are difficult to separate, whereas the pupae are the best stage to distinguish the species. The female of S. margaritatum   n. sp. differs from most known females of the inaequale   group by the unpatterned scutum ( Fig. 1 View FIGURES 1–2 ). The female scutum of the new species is similar to that of S. petropoliense Coscarón   , which also has no pattern, but the latter species has the scutum more densely covered with hairs than does S. margaritatum   n. sp. The anal lobe of S. margaritatum   n. sp. has a small protuberance near the cercus ( Fig. 12 View FIGURES 3–13 ); this structure can be used to distinguish this species from some species in the subgenus Inaequalium   . Variation was observed in the female cibarium of the new species. One of the five specimens we examined did not have the central region of the cibarium protuberant, which is typical of species of Inaequalium   ( Figs. 3, 4 View FIGURES 3–13 ). This variant could be the result of some abnormality; more specimens will need to be examined to verify our finding. Based on the original description ( Pessoa et al. 2005), the female of S. maranguapense   also lacks the typical central elevation in the cibarium. Males of several species in the subgenus Inaequalium   have a pair of rounded silver spots on the anterolateral area of the scutum, but the edges of these spots are not as well defined as the ones of the new species ( Fig. 14 View FIGURES 14–22 ). Also, males of the new species can be distinguished from the other species by the structure of the gonostylus and ventral plate ( Figs. 23, 26 View FIGURES 23–26 ). They also can be recognized by the configuration and number of gill filaments ( Figs. 27, 31 View FIGURES 27–32 ). The pupa of the new species has a gill with four filiform filaments, which distinguishes it from almost all other species in the subgenus Inaequalium   . Simulium maranguapense   also has a gill with four filaments, but the filaments are distinctly inflated ( Pessoa et al. 2005). The larva of S. margaritatum   n. sp. has a pigmented subesophageal ganglion ( Fig. 36 View FIGURES 35–42 ), which distinguishes it from the larvae of S. clavibranchium Lutz   , S. diversibranchium Lutz   , S. inaequale (Paterson & Shannon)   , S. leopoldense (Strieder & Py­Daniel)   , S. nahimi Py­Daniel   , S. maranguapense   , S. nogueirai D’Andretta & González   , S. rappae Py­Daniel & Coscarón   , S. subclavibranchium Lutz   , S. subnigrum Lutz   , and S. travassosi D’Andretta & D’Andretta. Larvae   of S. botulibranchium Lutz   and S. petropoliense   also have a pigmented subesophageal ganglion, but can be distinguished by the shape of the postgenal cleft, which is shallower than in S. margaritatum   n. sp. For the remaining species of the subgenus Inaequalium   , we do not have information about the pigmentation of the subesophageal ganglion. The larvae of S. margaritatum   n. sp. also can be distinguished from other species in this subgenus with known larvae by the number and configuration of the gill filaments, after dissection of the gill histoblast.

Etymology

The name of this new species is derived from Latin and means “adorned with pearls”, in reference to the two well­defined, silver spots, located on the anterolateral region of the male scutum.

Distribution

Simulium margaritatum   n. sp. has been collected only in the central region of Bahia State, Brazil, in the Chapada Diamantina National Park and surrounding area (see Material Examined).

Bionomics

Larvae and pupae were collected in six small, rock­bottomed streams in open areas, exposed to sunlight, usually in areas with a thin layer of water and low water velocity. The width of these streams varied from 0.2 to 1.5 m (mean = 0.7 m, SD = 0.55). The streams were located at altitudes from 770 to 1683 m. For substrate, larvae and pupae used trailing vegetation, deciduous leaves, and rocks. The streams had a mean water temperature of 19 o C (SD = 3.8), electrical conductivity from 20 to less than 40 µS/cm, and a mean pH of 4.2 (SD = 0.2). Females did not bite humans during the field work.

Material examined

Holotype ( INPA). Brazil, Bahia State, Itaitê Municipality. Rumo village, Chapadinha, small tributary of the Urubu River (#25), 13 o 11’S 41 o 10’W, 29.vii.2005 (N Hamada, M Pepinelli) – 1 male (pinned), with pupal exuviae in glycerine. GoogleMaps  

Paratypes. Brazil, Bahia State, Piatã Municipality. Serra dos Barbados: Córrego Forquilha (#47), 13 o 17’S 41 o 54’W, 06.viii.2005 (N Hamada, M Pepinelli and VL Landeiro) – 5 larvae (L), 5 pupae (P), 1 male (M), with pupal exuviae in glycerine ( INPA) GoogleMaps   .

Palmeiras Municipality. Parque Nacional Chapada Diamantina : small stream that cross the trail to Cachoeira da Fumaça (#34), 12 o 36’S 41 o 27’W, 31.vii.2005 (N Hamada, M Pepinelli & VL Landeiro) – 1M, 1 female (F) with pupal exuviae in glycerine, 5P, 5L ( MZUSP); small stream that cross the trail to Cachoeira da Fumaça (#35) 12 o 36’S 41 o 27’W, 31.vii.2005 (N Hamada, M Pepinelli & VL Landeiro) – 2M, 1F, 5P, 5L ( INPA) GoogleMaps   .

Itaitê Municipality. Urubu River (#24), Chapadinha, Rumo village , 13 o 11’S 41 o 10’W, 29.vii.2005 (N Hamada, M Pepinelli) – 5P, 5L ( INPA) GoogleMaps   ; small tributary of Urubu River (#25), Chapadinha, Rumo village , 13 o 11’S 41 o 10’W, 29.vii.2005 (N Hamada, M Pepinelli) – 5P, 5L, 2F ( INPA) GoogleMaps   . Rio de Contas Municipality. (#57), first stream in the trail to Mocotó waterfall, Mato Grosso village, 13 o 25’S 41 o 50’W, 10.viii.2005 (N Hamada, M Pepinelli & VL Landeiro) – 1F ( INPA) GoogleMaps   .

Other material examined Simulium inaequale   . Brazil, São Paulo state, Botucatu Municipality (#13), 22 o 54’S  

48 o 23’W, 11.v.2004 (N Hamada, M Pepinelli) – 2 last­instar larvae in ethanol ( INPA). Simulium clavibranchium   . Brazil, São Paulo state, São José do Barreiro Municipality  

(#19), 22 o 46’S 44 o 31’W 14.v.2004 (N Hamada, M Pepinelli) – 5 last­instar larvae in ethanol ( INPA) GoogleMaps   .

Simulium subclavibranchium   . Brazil, Minas Gerais state, Camanducaia Municipality, Monte Verde district (#45), 22 o 52’S 46 o 02’W, 23.v.2004 (N Hamada, M Pepinelli) – 2 lastinstar larvae in ethanol ( INPA) GoogleMaps   .

Simulium subnigrum   . Brazil, Rio Grande do Sul state, Sapiranga Municipality (#4), 05 o 02’S 67 o 27’W, 03.xi.2005 (N Hamada) – 2 last­instar larvae in ethanol ( INPA) GoogleMaps   .

Simulium rappae   . Brazil, São Paulo state, Brotas Municipality (#8), 22 o 16’S 48 o 11’W, 10.v.2004 (N Hamada, M Pepinelli) – 2 last­instar larvae in ethanol ( INPA) GoogleMaps   .

Simulium nogueirai   . Brazil, São Paulo state, São José do Barreiro Municipality (#19), 22 o 46’S 44 o 31’W, 14.v.2004 (N Hamada, M Pepinelli) – 5 last­instar larvae in ethanol ( INPA) GoogleMaps   .

Simulium diversibranchium   . Brazil, São Paulo state, Campos do Jordão Municipality, Parque Estadual Campos do Jordão (#34), 22 o 39’S 45 o 27’W, 18.v.2004 (N Hamada, M Pepinelli) – 1 last­instar larva in ethanol ( INPA) GoogleMaps   .

Simulium travassosi   . Brazil, São Paulo state, Botucatu Municipality (#13), 22 o 54’S 48 o 23’W, 11.v.2004 (N Hamada, M Pepinelli) – 1 last­instar larva in ethanol ( INPA) GoogleMaps   .

Simulium botulibranchium   . Brazil, Minas Gerais state, Camanducaia Municipality, Monte Verde district (#45), 22 o 52’S 46 o 02’W, 23.v.2004 (N Hamada, M Pepinelli) – 2 lastinstar larvae in ethanol ( INPA) GoogleMaps   .

Simulium petropoliense   . Brazil, Rio de Janeiro state, Petrópolis Municipality (#14), 22 o 27’S 43 o 06’W, 14.ix.2005 (N Hamada, M Pepinelli) – 5 last­instar larvae in ethanol, 3 pinned females with pupal exuviae in glycerine ( INPA) GoogleMaps   .

Simulium nahimi   . Brazil, Rondônia, Vilhena Municipality, small stream on the road to Usina do Rio Vermelho (#34), 12 o 53’S 60 o 11’W, 25.vii.2004, (N Hamada) – 2 last­instar larvae in ethanol ( INPA) GoogleMaps   .

INPA

Instituto Nacional de Pesquisas da Amazonia

MZUSP

Museu de Zoologia da Universidade de Sao Paulo

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Simuliidae

Genus

Simulium

Loc

Simulium (Inaequalium) margaritatum Pepinelli, Hamada & Luz

Pepinelli, Mateus, Hamada, Neusa & Luz, Sérgio Luiz Bessa 2006
2006
Loc

Simulium margaritatum

Pepinelli & Hamada & Luz 2006
2006
Loc

S. margaritatum

Pepinelli & Hamada & Luz 2006
2006
Loc

S. margaritatum

Pepinelli & Hamada & Luz 2006
2006
Loc

S. margaritatum

Pepinelli & Hamada & Luz 2006
2006
Loc

S. margaritatum

Pepinelli & Hamada & Luz 2006
2006
Loc

S. margaritatum

Pepinelli & Hamada & Luz 2006
2006
Loc

S. margaritatum

Pepinelli & Hamada & Luz 2006
2006
Loc

S. maranguapense

Pessõa, Ríos-Velásquez & Py-Daniel 2005
2005
Loc

S. nahimi Py­Daniel

Py-Daniel 1984
1984
Loc

S. rappae Py­Daniel & Coscarón

Py-Daniel & Coscaron 1982
1982
Loc

S. petropoliense Coscarón

Coscaron 1981
1981
Loc

S. petropoliense

Coscaron 1981
1981
Loc

S. botulibranchium

Lutz 1910
1910
Loc

S. clavibranchium

Lutz 1910
1910
Loc

S. diversibranchium

Lutz 1910
1910
Loc

S. subclavibranchium

Lutz 1910
1910
Loc

S. subnigrum

Lutz 1910
1910
Loc

S. botulibranchium

Lutz 1910
1910