Simulium (Gomphostilbia) confertum Takaoka & Sofian-Azirun, sp. nov.
Creators: name: Takaoka, Hiroyuki
name: Sofian-Azirun, Mohd
name: Ya'Cob, Zubaidah
name: Chen, Chee Dhang
name: Lau, Koon Weng
name: Pham, Xuan Da
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Simuliidae
Simulium
Simulium confertum

description: Simulium (Gomphostilbia) confertum Takaoka & Sofian-Azirun sp. nov.
(Figs. 1 A– 3I)
Female. Body length 2.0 mm. Head. Slightly narrower than width of thorax. Frons dark brown, densely covered with whitish-yellow scale-like recumbent short hairs interspersed with few dark longer hairs along each lateral margin; frontal ratio 1.81:1.00:2.35; frons:head ratio 1.0:4.3. Fronto-ocular area well developed, narrow, directed dorsolaterally. Clypeus dark brown, white pruinose, densely covered with whitish-yellow hairs interspersed with several dark longer hairs on each side. Labrum 0.57 times length of clypeus. Antenna composed of scape, pedicel and nine flagellomeres, dark brown except scape, pedicel, and base of first flagellomere whitish yellow. Maxillary palp composed of five segments, light to medium brown, proportional lengths of third, fourth, and fifth segments 1.0:1.1:2.1; third segment (Fig. 1 A) somewhat widened; sensory vesicle (Fig. 1 A) medium-sized, ellipsoidal (0.3 times length of third segment), with medium-sized opening. Maxillary lacinia with 9 or 10 inner and 10 or 11 outer teeth. Mandible (Fig. 1 B) with 19 inner teeth and several rounded minute rudimentary teeth except basal one having sharply pointed apex. Cibarium (Fig. 1 C) medially forming sclerotized plate folded forward from posterior margin, with moderately sclerotized mediolongitudinal ridge having V-shaped apex. Thorax. Scutum dark brown except anterolateral calli ochreous, thinly pruinose and shiny when illuminated at certain angles, densely covered with yellow scale-like recumbent hairs; three longitudinal vittae (one medial, two submedial) faintly visible when viewed at certain angles. Scutellum medium brown, covered with yellow short hairs and dark-brown long upright hairs along posterior margin. Postnotum dark brown, shiny when illuminated at certain angles, and bare. Pleural membrane bare. Katepisternum longer than deep, medium brown, shiny when illuminated at certain angles, moderately covered with fine short hairs. Legs. Foreleg: coxa whitish-yellow; trochanter dark yellow to light brown; femur light brown with apical cap medium brown (though extreme tip yellowish); tibia white except little more than apical one-fourth dark brown, densely covered with white fine hairs on little more than basal threefourths; tarsus brownish-black, with moderate dorsal hair crest; basitarsus moderately dilated, 5.9 times as long as its greatest width. Midleg: coxa medium brown except posterior surface dark brown; trochanter light brown except base yellowish; femur light brown with base yellowish and apical cap medium brown (though extreme tip yellowish); tibia dark brown to brownish black except basal one-third whitish (though inner surface more extensively white on basal two-thirds), covered with whitish and yellowish fine hairs on posterior and inner surfaces of basal three-fourths; tarsus dark brown to brownish-black except little less than basal half of basitarsus yellow. Hind leg: coxa medium brown; trochanter yellow; femur light brown with base yellowish and apical cap medium brown (though extreme tip yellowish); tibia (Fig. 1 D) whitish on basal half, brownish black on apical onefourth, grayish on most of intermediate portion though anterior and posterior margins somewhat darkened, densely covered with whitish fine hairs on outer and posterior surfaces of basal three-fourths; tarsus brownish-black except basal two-thirds of basitarsus (though base light brown) and basal half of second tarsomere white; basitarsus (Fig. 1 E) narrow, nearly parallel-sided though slightly narrowed on apical one-half, 6.04 times as long as wide, and 0.71 and 0.62 times as wide as greatest widths of tibia and femur, respectively; calcipala (Fig. 1 E) slightly shorter than width at base, and 0.59 times as wide as greatest width of basitarsus. Pedisulcus (Fig. 1 E) well developed. Claw (Fig. 1 F) with large basal tooth 0.48 times length of claw. Wing. Length 1.9 mm. Costa with dark spinules and hairs except basal patch of hairs yellow. Subcosta with dark hairs except near apex bare. Hair tuft on base of radial vein yellow. Basal portion of radius fully haired; R1 with dark spinules and hairs; R2 with hairs only. Basal cell absent. Halter. White except basal portion darkened. Abdomen. Basal scale light ochreous, with fringe of whitish-yellow hairs. Dorsal surface of abdomen medium to dark brown except segment 2 whitish (though somewhat darkened narrowly along posterior margin), moderately covered with dark short to long hairs (except segment 2 with yellow fine hairs); tergites of segments 2 and 6–9 shiny when illuminated at certain angles. Ventral surface of segment 2 whitish, those of segments 3–5 grayish yellow, those of segments 6 and 7 medium brown and that of segment 8 medium to dark brown; sternal plate on segment 7 undeveloped. Genitalia. Sternite 8 (Fig. 1 G) bare medially, with 22 or 23 medium-long to long hairs together with few slender short hairs on each side. Ovipositor valves (Fig. 1 G) tongue-like, thin, membranous, moderately covered with microsetae interspersed with two short hairs; inner margins slightly sinuous, somewhat sclerotized, and moderately separated from each other. Genital fork (Fig. 1 H) of usual inverted-Y form, with slender stem; arms of moderate width, moderately folded medially. Paraproct in ventral view (Fig. 1 I) somewhat concave anterolaterally, with three sensilla on anteromedial surface; paraproct in lateral view (Fig. 1 J) slightly produced ventrally beyond ventral tip of cercus, 0.53 times as long as wide, with 19 or 20 medium-long to long hairs on ventral and lateral surfaces. Cercus in lateral view (Fig. 1 J) short, rounded posteriorly, 0.4 times as long as wide. Spermatheca ellipsoidal, much longer than its greatest width (exact width not measurable due to shrinkage of spermatheca), well sclerotized except duct and small area near juncture with duct unsclerotized, and with many fissures on outer surface; internal setae absent; both accessory ducts slender, slightly wider in diameter than major one.
Male. Body length 2.2 mm. Head. Nearly as wide as thorax. Upper eye medium brown, consisting of 14 vertical columns and 15 horizontal rows of large facets. Face dark brown, white pruinose. Clypeus dark brown, whitish pruinose, densely covered with golden-yellow scale-like medium-long hairs (mostly directed upward) interspersed with several dark brown longer hairs. Antenna composed of scape, pedicel and nine flagellomeres, dark brown except scape and pedicel dark yellow to light brown and base of first flagellomere whitish-yellow; first flagellomere elongate, 1.9 times length of second one. Maxillary palp light to medium brown, with five segments, proportional lengths of third, fourth, and fifth segments 1.0:1.2:2.6; third segment (Fig. 2 A, B) somewhat widened apically; sensory vesicle (Fig. 2 A, B) ellipsoidal or globular, small (0.17–0.20 times length of third segment), and with small opening. Thorax. Scutum brownish-black, thinly white pruinose and shiny on narrow portions along lateral margins and prescutellar area when illuminated at certain angles, and densely covered with golden-yellow short recumbent hairs. Scutellum dark brown with yellow short hairs and dark-brown upright longer hairs. Postnostum dark brown, white pruinose and shiny when illuminated at certain angles, and bare. Pleural membrane bare. Katerpisternum longer than deep, dark brown, thinly white pruinose and shiny when illuminated at certain angles, with dark short hairs. Legs. Foreleg: coxa yellow; trochanter light brown; femur light brown with apical cap medium brown (though extreme tip yellowish); tibia light to dark brown except basal three-fourths of outer surface whitish, and densely covered with white fine hairs on outer surface, which are shiny when illuminated at certain angles; tarsus brownish-black, with moderate dorsal hair crest; basitarsus somewhat dilated, 7.0 times as long as its greatest width. Midleg: coxa dark brown except posterior surface brownish black; trochanter light brown; femur light brown and apical cap medium brown (though extreme tip yellowish); tibia dark brown to brownish-black except basal one-third yellow; tarsus brownish-black except basal tip of basitarsus dark yellow. Hind leg: coxa light brown; trochanter yellow; femur light brown with base yellowish and apical cap medium brown; tibia (Fig. 2 C) yellow on little less than basal half and dark-brown to brownish-black on rest; tarsus brownish-black except basal two-fifths of basitarsus (though base medium brown, and its border not well defined) and little less than basal half of second tarsomere whitish yellow; basitarsus (Fig. 2 D) much enlarged, spindle-shaped, 4.0 times as long as wide, and 0.92 and 1.00 times as wide as greatest widths of tibia and femur, respectively; calcipala (Fig. 2 D) slightly shorter than wide, and 0.37 times as wide as greatest width of basitarsus. Pedisulcus (Fig. 2 D) well developed. Wing. Length 1.7 mm. Other features as in females except subcosta bare. Halter. Whitish except basal portion and narrow portion along anterior margin grayish. Abdomen. Basal scale dark brown, with fringe of light-brown hairs. Dorsal surface of abdomen medium brown to brownish-black except basal one-third of segment 2 yellow, covered with light to dark-brown short to long hairs; segments 2 and 5–8 each with pair of shiny dorsolateral or lateral patches; ventral surface of segment 2 white, those of segments 3 and 4 grayish, and those of other segments medium to dark brown. Genitalia. Coxite in ventral view (Fig. 2 E) nearly rectangular, 1.86 times as long as its greatest width. Style in ventral view (Fig. 2 E) bent inward, nearly parallel-sided toward apex, and with apical spine; style in ventrolateral view (Fig. 2 F) slightly narrowed from base toward apex, with truncated apex. Ventral plate in ventral view (Fig. 2 E) with body transverse, 0.56 times as long as wide, widest basally, with lateral margins slightly emarginated medially, anterior margin produced anteromedially, and posteroventral margin concave submedially, densely covered with microsetae on ventral surface; basal arms of moderate length, directed forward, nearly parallel-sided; ventral plate in lateral view (Fig. 2 G) moderately produced ventrally; ventral plate in caudal view (Fig. 2 H) trapezoidal, with ventral margin nearly straight or slightly concave medially, densely covered with microsetae on posterior surface. Median sclerite (Fig. 2 G, I) thin, plate-like, wide. Paramere (Fig. 2 J) of moderate size, with three long hooks and one medium-long hook. Aedeagal membrane (Fig. 2 J) sparsely setose; dorsal plate not defined. Ventral surface of abdominal segment 10 (Fig. 2 K, L) weakly sclerotized near anterior margin, without distinct hairs near posterior margin. Cercus (Fig. 2 K, L) small, rounded, with 14–16 hairs.
Pupa. Body length 2.3 mm. Head. Integument yellow, moderately covered with small round tubercles; antennal sheath without protuberances; frons with three pairs of long trichomes with coiled or uncoiled apices (Fig. 3 A); face with pair of long trichomes with coiled apices (Fig. 3 B); three frontal trichomes on each side arising close together, subequal in length to one another and slightly longer than facial one. Thorax. Integument yellow, moderately covered with round tubercles, with three long anterodorsal trichomes with coiled apices (Fig. 3 C), two long anterolateral trichomes (one with coiled apex, one with uncoiled apex) (Fig. 3 D), one medium-long mediolateral trichome with uncoiled apex (Fig. 3 E), and three short ventrolateral trichomes with uncoiled apices (one much shorter than two others) (Fig. 3 F), on each side; all trichomes unbranched. Gill (Fig. 3 G) composed of eight slender thread-like filaments, arranged as [3 +(1+2)]+2 filaments, or [(2+1)+(1+2)]+2 filaments from dorsal to ventral, with medium-long common basal stalk having somewhat swollen basal fenestra ventrally (often partially broken) at base; common basal stalk 0.67–0.75 times length of interspiracular trunk; dorsal and middle triplets sharing short stalk; dorsal triplet composed of three individual filaments arising at same level from short stalk in female pupa, but dorsal triplet composed of one individual and two paired filaments with short secondary stalk in male pupa; ventral paired filaments with medium-long stalk 0.92–1.09 times length of common basal stalk; primary stalk of dorsal triplet lying against that of lower pair at angle of 45–60 degrees when viewed laterally; all filaments light brown, gradually tapered toward apex; six filaments of dorsal and middle triplets subequal in length (1.5–1.9 mm long including their own stalks and common basal stalk) and thickness to one another; two filaments of ventral pair subequal in length (2.6 mm) and thickness to each other, and 1.5 times as thick as six other filaments when compared basally; cuticle of all filaments with well-defined annular ridges and furrows though becoming less marked apically, densely covered with minute tubercles. Abdomen. Dorsally, segments 1, 2 and 9 light yellow, others faintly yellowish on basal areas of hooks or spine-combs; all segments without tubercles; segment 1 with one unbranched slender medium-long hair-like seta on each side; segment 2 with one unbranched slender mediumlong hair-like seta and four or five short setae submedially on each side; segments 3 and 4 each with four hooked spines and one short somewhat spinous seta on each side; segment 5 lacking spine-combs; segments 6–9 each with spine-combs in transverse row and comb-like groups of minute spines on each side; segment 9 with pair of flat triangular terminal hooks, of which outer margin 1.8–2.2 times length of inner margin and crenulated (Fig. 3 H). Ventrally, segment 4 with one unbranched hooklet and few unbranched slender short setae on each side; segment 5 with pair of bifid hooks submedially and few short unbranched slender setae on each side; segments 6 and 7 each with pair of bifid inner and unbranched outer hooks somewhat spaced from each other and few short unbranched slender setae on each side; segments 4–8 each with comb-like groups of minute spines. Each side of segment 9 with three grapnel-shaped hooklets. Cocoon (Fig. 3 I). Wall-pocket-shaped, thinly woven, widely extended ventrolaterally; anterior margin not thickly woven, without bulge or projection; posterior half with floor roughly woven; individual threads invisible; 2.9–3.0 mm long by 1.8–2.2 mm wide.
Mature larva. Unknown.
Type material. HOLOTYPE: Female, reared from a pupa collected from a moderately flowing stream (width 1–3 m, water temperature 16.0˚C, partially shaded, altitude 1,492 m, 12°07’59.430” N / 108°35’42.001” E), Da Chais (45 km from Dalat), Lac Duong, Lam Dong Province, southern Vietnam, 24-IV-2014, by H. Takaoka, M. Sofian-Azirun, Z. Ya’cob, C.D. Chen & K.W. Lau. PARATYPES: One male, one pharate male and two pupae, same data as those of the holotype.
Biological notes. The pupae of this new species were collected from stalks and leaves of trailing grasses in the water. Associated species were S. (S.) chamlongi Takaoka & Suzuki, S. (S.) nodosum Puri and S. (S.) rufibasis Brunetti.
Etymology. The species name confertum refers to the gill filaments directed forward close together. The Latin adjective ‘confertus’ signifies ‘closely packed’.
Remarks. Simulium (G.) confertum sp. nov. is placed in the S. asakoae species-group, as defined by Takaoka (2012) based on the enlarged male hind basitarsus (Fig. 2 D), ventral plate slightly emarginated medially (Fig. 2 E), yellow hair tuft of the base of the radial vein, and whitish yellow fore coxae of both female and male adults.
The male of S. (G.) confertum sp. nov. is similar to S. (G.) chiangdaoense Takaoka & Srisuka described from Thailand, S. (G.) tamdaoense Takaoka, Sofian-Azirun & Ya’cob described from Vietnam, and S. (G.) tanahrataense Takaoka, Sofian-Azirun & Ya’cob described from Peninsular Malaysia, in having a similar number of upper-eye facets (in 13 or 14 vertical columns and 15 or 16 horizontal rows in S. (G.) chiangdaoense, in 14 vertical columns and 14 horizontal rows in S. (G.) tamdaoense and in 14 vertical columns and 15 horizontal rows in S. (G.)
tanahrataense) (Takaoka et al. 2014a, c; Takaoka and Srisuka 2009). However, the male of S. (G.) confertum sp. nov. is distinguished from S. (G.) chiangdaoense and S. (G.) tanahrataense by the absence of hairs on the subcosta, and from S. (G.) tamdaoense by the hind basitarsus which is yellow on less than the basal half (cf., yellow on the basal half in S. (G.) tamdaoense), and paramere without hairs on the outer surface of its arms (cf., hairs present on the outer surface of the arms in S. (G.) tamdaoense).
The pupa of S. (G.) confertum sp. nov. is distinguished from S. (G.) chiangdaoense by the simple wall-pocketshaped cocoon (Fig. 3 I) (cf., cocoon with a long anterodorsal projection in S. (G.) chiangdaoense), from S. (G.) tamdaoense by the dorsal and middle triplets of the gill bearing an extremely short common stalk (Fig. 3 G) (cf., with short common stalk in S. (G.) tamdaoense), and from S. (G.) tanahrataense by the narrower terminal hooks (i.e., length ratio of the outer margin against the inner margin is 1.8–2.2) (Fig. 3 H) (cf., 2.7–2.8 in S. (G.) tanahrataense)
description: Published as part of Takaoka, Hiroyuki, Sofian-Azirun, Mohd, Ya'Cob, Zubaidah, Chen, Chee Dhang, Lau, Koon Weng & Pham, Xuan Da, 2015, The black flies (Diptera: Simuliidae) from Thua Thien Hue and Lam Dong Provinces, Vietnam, pp. 1-96 in Zootaxa 3961 (1) on pages 7-13, DOI: 10.11646/zootaxa.3961.1.1, http://zenodo.org/record/288572