Simulium (Psaroniocompsa) stellatum Gil-Azevedo, Figueiró & Zog, 2005, sp. n.
Creators: name: Gil-Azevedo, Leonardo
name: Figueiró, Ronaldo
name: Zog, Marilza Maia-Her-
Publisher: name: Zenodo
Year: 2005
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Simuliidae
Simulium
Simulium stellatum

description: Simulium (Psaroniocompsa) stellatum sp. n.
(Figs. 1–5)
Type Material. Holotype: BRAZIL, Minas Gerais State, Itamonte, Itatiaia National Park, Brejo da Lapa, 44º44’13”W 22º21’30”S, 2,156 m altitude (07/VI/2004, Gil­Azevedo, L. & Figueiró, R. coll.) [LSO­006]: 1 female with pupal pelt (pinned). Paratypes: BRAZIL, Minas Gerais State, Itamonte, Itatiaia National Park, Brejo da Lapa, 44º44’13”W 22º21’30”S, 2,156 m altitude (07/VI/2004, Gil­Azevedo, L. & Figueiró, R. coll.) [LSO­ 007]: 3 females with pupal pelts and 3 males with pupal pelts (pinned); 2 females with pupal pelts, 1 male with pupal pelt and 6 larvae (slides), 15 pupae and 34 larvae (spirit). [INPA]: 5 pupae and 5 larvae (spirit). [MLP]: 5 pupae and 5 larvae (spirit). [BMNH]: 5 pupae and 5 larvae (spirit). BRAZIL, Rio de Janeiro State, Itatiaia, Itatiaia National Park, Agulhas Negras range, 44º41’36”W 22º22’38”S, (07/VI/2004, Gil­Azevedo, L. & Figueiró, R. coll.) [LSO­008]: 5 pupae and 10 larvae (spirit). BRAZIL, Rio de Janeiro State, Itatiaia, Itatiaia National Park, Três Picos, 44º35’27”W 22º25’23”S, 1,576 m altitude (10/II/2003, Gil­Azevedo, L. & Figueiró, R. coll.) [LSO­009]: 2 pupae.
Diagnosis. Female with nudiocular area reduced and rounded; teeth of mandible on external side reduced; inner margin of gonapophysis sclerotized. Male with small sublateral gonostyle spur. Pupa with 4 gill filaments; dorsal primary branch bifurcated at about half length of ventral primary branch; filaments thick at primary branches and narrowing distally, with surface covered by large and small rounded tubercles. Larval head with 1 + 1 median longitudinal spots and 1 + 1 small anterolateral spots; postgenal cleft rounded.
Female. General body colour black. Body length 2.4–2.8 mm (n = 3); mesothorax length 1.1–1.3 mm, mesothorax width 0.8–0.9 mm (n = 4); wing length 2.5 mm, wing width 1.2 mm (n = 1).
Head dichoptic with black eyes; nudiocular area small and rounded (Fig. 1 a, b). Frons, clypeus, and occiput black with silver pruinosity; frons higher than wide. Antennae with silver pruinosity; scape and pedicel light brown, flagellomeres black. Mouthparts dark; palp and labium black with silver pruinosity, labrum brown. Mandible with about 34 teeth on internal side and about five poorly developed teeth on external side. Maxilla with about 25 teeth; palp with its last article about 3 times longer than penultimate article; Lutz’s organ length about 1/3 of basal article length. Cibarium with arms and basal portion sclerotized; basal portion with medial region concave and unarmed, its sides armed with 4 rows of teeth each (Fig. 1 c, d).
Scutum entirely black, with lateral silver pruinosity band extending from anterior to distal region. Scutum with sets of golden setae, arranged in broken lines running along whole length of scutum; 3 medial lines distinct (Fig. 1 e). Humeri black with golden setae and silver pruinosity. Scutellum black with dark bristles. Metanotum and pleural region black with silver pruinosity. Wing veins: C with spines and setae, Sc and basal portion of R bare, R1 with spines, Rs with setae (Fig. 1 f, g). Halter with black base and light­yellow apex. Fore leg with coxa, trochanter, and femur pale yellow; tibia with proximal region pale yellow with distal 1/3 black; tarsus black (Fig. 2 a). Mid leg with coxa black; trochanter and femur pale yellow; tibia, basitarsus, second tarsomere and third tarsomere background pale yellow with distal apex black; remaining tarsomeres black (Fig. 2 b). Hind leg with coxa black; trochanter pale yellow; femur and tibia with proximal region pale yellow and distal region black; basitarsus proximally pale yellow with distal 1/3 black; second tarsomere with proximal 1/3 pale yellow and distal region black; other tarsomeres black (Fig. 2 c). Calcipala and pedisulcus present. All legs with dark bristles and scalelike setae. Hind leg claws bearing small triangular subbasal tooth (Fig. 2 d).
Abdomen with silver pruinosity and golden setae; segments I–IV velvety black, remaining segments metallic black. Gonapophysis distally straight; inner margins sclerotized and subparallel, diverging distally; with rounded internal angle (Fig. 2 e). Cerci subtrapezoidal; paraprocts about 3 times longer than wide; paraproct length about twice cercus length (Fig. 2 f). Genital fork stem as long as lateral arms; lateral arms short and thin; stem entirely sclerotized and lateral arms partially sclerotized; lateral arms forming a subtriangle space (Fig. 2 g). Spermatheca suboval and heavily sclerotized (Fig. 2 h), with sets of spicules; duct hyaline.
Male. General body colour black. Body length 2.2–2.7 mm (n = 3); mesothorax length 1.0– 1.1 mm, mesothorax width 0.8–0.9 mm (n = 4); wing length 1.9 mm, wing width 1.1 mm (n = 1).
Head holoptic with black eyes. Frons, clypeus, mouthparts, occiput, and antennae coloration as in female. Lutz’s organ length about 1/5 basal article length.
Thorax coloration, wing veins, and halter coloration as in female (Fig. 3 a).
Leg coloration different from that of female. Fore leg with coxa and trochanter pale yellow; femur background pale yellow with distal apex black; tibia ventrally pale yellow and dorsally black; tarsus black (Fig. 3 b). Mid leg with coxa and trochanter black; femur and tibia pale yellow with transversal medial band black; basitarsus proximally pale yellow with distal 1/3 black; second tarsomere proximally pale yellow and distally black; remaining tarsomeres black (Fig. 3 c). Hind leg with coxa black; trochanter pale yellow; femur with proximal 1/3 pale yellow, medial 1/3 light brown, and distal 1/3 black; tibia proximally pale yellow and distally black; basitarsus proximally pale yellow with distal 1/ 3 black; second tarsomere with proximal 1/3 pale yellow and distal region black; other tarsomeres black (Fig. 3 d). All legs with dark bristles and scalelike setae.
Abdomen black with silver pruinosity and golden setae, segments V–VII with silver spots. Gonocoxite subretangular; gonostyle small, subquadrangular, with 1 tiny subapical sublateral spine (Fig. 3 e). Ventral plate subrectangular with sclerotized basal arms, concave pointed apex (Fig. 3 f). Median sclerite elongated and flattened. Paramere with 3 subparallel teeth well developed; medial teeth convergent.
Pupa. Pupa length 3.0– 3.4 mm (n = 5); gill length 3.4–4.1 mm (n = 4); cocoon length ventrally 3.5–4.2 mm (n = 6); cocoon anterodorsal projection length 0.9–1.3 mm (n = 5).
Gill as long as cocoon (Fig. 4 a), with 4 filaments directed forward; main trunk immediately giving rise to 2 primary branches each with a single bifurcation; dorsal primary branch bifurcating about half length of ventral primary branch; all filaments of equal size, thick at primary branches and narrowing distally (Fig. 4 b); surface of gill filaments covered with large and small rounded tubercles (Fig. 4 c); apex of all filaments digitlike (Fig. 4 d).
Head with 2 + 2 bifid hairlike frontal trichomes, 1 + 1 bifid hairlike facial trichomes (Fig. 4 e); head covered with small rounded tubercles. Thorax with 5 + 5 bifid hairlike anterodorsal trichomes; thorax covered with small rounded tubercles. Abdominal chaetotaxy: tergites III–IV each with 4 + 4 anteriorly directed hooks on posterior margin; tergites VI–IX each with transverse row of small spines on anterior margin; tergite IX with 1 + 1 short, slightly curved terminal spur. Sternites V–IX each with transverse row of microspines; sternites V–VII each with 2 + 2 anteriorly directed bifid or trifid hooks on posterior margin.
Cocoon light brown, with definable shape and symmetrical (Fig. 4 f); slipper shaped (Fig. 4 a) and attached to substratum by lateral expansion; fabric compact and thin (Fig. 4 f); cocoon bearing well developed anterodorsal projection, which surpasses cocoon base (Fig. 4 f); rim of aperture not reinforced (Fig. 4 f); floor connected to lateral wall of roof; cocoon generally covering abdomen and part of thorax of pupa (Fig. 4 a).
Larva (final instar). General coloration yellowish white. Maximum length 6.0– 7.2 mm (average = 6.7 mm, n = 10); head capsule dorsal length 0.73–1.00 (average = 0.84 mm, n = 10), dorsal width 0.55–0.82 (average = 0.68 mm, n = 10); gill histoblast length in situ 0.55–0.68 mm (average = 0.61 mm, n = 10), width 0.45–0.55 mm (average = 0.49 mm, n = 10).
Head capsule (in dorsal view) with dark spots, 1 + 1 basal submedian transverse spots, 1 + 1 median longitudinal and 1 + 1 small anterolateral spots (Fig. 5 a). Hypostoma with median tooth smaller than 1 + 1 lateral teeth; 3 + 3 sublateral teeth small; lateral margin of hypostoma with 2 or 3 paralateral teeth and about 4 serrations per side; hypostoma with 4 + 4 setae (Fig. 5 b, 5c). Postgenal cleft longer than wide, rounded; hypostomal bridge twice as long as hypostoma (Fig. 5 b). Antennae as long as base of labral fan, with articles long, subequal in size (Fig. 5 d). Labral fan with 42–47 rays. Mandibular teeth: 1 apical, 2 external, 3 subapical, about 8 internal teeth; 1 large mandibular serration. Subesophageal ganglion not pigmented.
Thorax and abdomen yellowish white, with greenish white regions (Fig. 5 e, f). Abdomen with 1 + 1 ventral tubercles (Fig. 5 g). Anal sclerite X shaped (Fig. 5 h); rectal organ with three branches, each with 8–10 lobes. Anal ring with about 67 rows of 9–13 hooks each.
Etymology. The species name stellatum is derived from Latin and means starry. The name refers to the scutal pattern and also to the first collection, which was made on a starry night.
Bionomics. Up to date, Simulium stellatum sp. n. has been found only at high altitude in Itatiaia National Park. Until now, only S. schmidtmummi in the subgenus Psaroniocompsa had been recorded above an elevation of 2,000 m. The immatures develop in springs with high levels of insolation and 4–16 ºC water temperature. They use submerged herbaceous riparian vegetation as a substrate.
description: Published as part of Gil-Azevedo, Leonardo, Figueiró, Ronaldo & Zog, Marilza Maia-Her-, 2005, Simulium (Psaroniocompsa) stellatum (Diptera: Simuliidae), a new black fly from a high mountain range in southeastern Brazil, pp. 1-12 in Zootaxa 922 on pages 2-10, DOI: 10.5281/zenodo.171080