Simulium (Gomphostilbia) dinakarani Anbalagan & Vijayan & Balachandran & Thiyonila & Surya 2020, sp. nov.
Creators: name: Anbalagan, Sankarappan
name: Vijayan, Suruliyandi
name: Balachandran, Chellapandian
name: Thiyonila, Berchmans
name: Surya, Aathmanathan
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Simuliidae
Simulium
Simulium dinakarani

description: Simulium (Gomphostilbia) dinakarani sp. nov.
(Figs. 1–3)
(Zoobank Ref. No: urn:lsid:zoobank.org:pub: 88E6EA69-35D2-4DC8-85BA-E1C9EEBB0E55)
Diagnosis. Female: scutum with 3 brownish-black longitudinal vittae, hind basitarsus 6.2 times as long as wide and Sternite 8 covered with 14–16 long hairs. Male: upper eye with 13 vertical columns and 16 horizontal rows of large facets, hind basitarsus spindle-shaped and 4.2 times as long as wide. Pupa: respiratory gill with 8 filaments and stalk of ventral pair 1.1–1.31 times as thick as primary stalk of middle triplet. Larva: 4 hypostomal bristles per side arrayed parallel to lateral margin and postgenal cleft 4.1 times as long as postgenal bridge.
Description. Female. Body length 3.8 mm. Head. Slightly narrower than thorax. Frons brownish-black, densely covered with yellowish-white recumbent hairs interspersed; frontal ratio 2.6:1.0:2.9; frons:head ratio 1.0:2.7. Fronto-ocular area well developed, narrow, directed dorsolaterally. Clypeus yellowish-black, densely covered with yellowish-white recumbent hairs interspersed with few to several dark longer hairs on each side. Labrum 0.8 times length of clypeus. Antenna composed of scape, pedicel and nine flagellomeres, dark brown except scape and pedicel yellow and basal extreme of first flagellomere light brown. Maxillary palp composed of 5 segments, light brown except first and second segment ochreous and third segment medium brown, proportional lengths of third, fourth, and fifth segments 1.0:0.9:2.0; third segment (Fig. 1A) widened apically; sensory vesicle (Fig. 1A) medium-sized (0.48 times length of 3 rd segment), with large-sized opening. Maxillary lacinia with 33 inner teeth. Mandible with 12 inner teeth and no distinct outer teeth, though outer margin indented near apex and appearing to have few to several vestigial teeth. Cibarium (Fig. 1B) medially forming sclerotized plate folded forward from posterior margin, with moderately sclerotized medio-longitudinal ridge with bifid apex. Thorax. Scutum dark brown except anterolateral calli dark ochreous, with 3 brownish-black longitudinal vittae (1 narrow median and 2 lateral), median vitta united anteriorly to anterior calli, lateral vittae united posteriorly to prescutellar area; scutum shiny when illuminated at certain angles, densely covered with yellow scale-like recumbent shorthairs interspersed with dark brown long upright hairs on prescutellar area. Scutellum shiny, with dark brown short hairs. Postnotum shiny and bare. Pleural membrane bare. Katepisternum medium to dark brown, longer than deep, shiny when illuminated at certain angles, densely covered with fine short hairs. Legs. Foreleg: coxa yellow; trochanter yellow except apical portion somewhat darkened; femur light brown; tibia brown; tarsus brownish black, with moderate dorsal hair crest; basitarsus slightly dilated, 6.3 times as long as its greatest width. Midleg: coxa yellowish brown except posterior surface dark brown; trochanter yellow to light brown; femur and tibia brown; tarsus brownish-black except basal 1/2 of basitarsus dark yellow. Hindleg: coxa yellowish brown; trochanter yellow; femur medium brown with base yellow and apical cap dark brown; tibia (Fig. 1C) light to dark brown with basal 1/4 white, covered with brownish fine hairs on outer and posterior surfaces; tarsus brownish-black except basal 2/3 of basitarsus (though base light brown); basitarsus (Fig. 1D) narrow, nearly parallel-sided, 6.2 times as long as wide, and 0.62 and 0.55 times as wide as greatest width of tibia and femur, respectively; calcipala (Fig. 1D) slightly shorter than width at base, and 0.41 times as wide as greatest width of basitarsus. Pedisulcus (Fig. 1D) well defined. Claw (Fig. 1E) with large basal tooth 0.4 times as long as claw. Wing. Length 2.0 mm. Costa with dark-brown spinules and light-brown hairs except basal patch of yellow hairs. Subcosta haired except near apex bare. Hair tuft on base of radial vein dark brown. Basal portion of radius fully haired. Basal cell absent. Halter. Clear white except basal stem darkened. Abdomen. Basal scale dark yellow, with fringe of yellowish-white hairs. Dorsal surface of abdomen medium to dark brown except segment 2 light brown with middle portion of tergite ochreous, moderately covered with dark short to long hairs; tergites of segments 2 and 6–9 shiny when illuminated at certain angles. Ventral surface of segments 2–4 creamy, those of other segments light to dark brown; sternite 7 undeveloped. Genitalia. Sternite 8 (Fig. 1F) well sclerotized and bare medially, covered with 14–16 long hairs on each side. Ovipositor valves tongue-like, thin, membranous, moderately covered with microsetae; inner margins convex, somewhat sclerotized, and slightly separated from each other. Genital fork (Fig. 1G) of usual inverted-Y form; stem slender and well sclerotized; arms of moderate width, lateral plate of each arm with thin lobe directed posteromedially and small stout projection directed anterodorsally. Paraproct in ventral view (Fig. 1H) concave anterolaterally, with 3 sensilla on anteromedial surface; paraproct in lateral view (Fig. 1I) much produced ventrally, 0.63 times as long as wide, with 6–8 medium-long to long hairs on ventral and lateral surfaces. Cercus in lateral view (Fig. 1I) short, rounded posteriorly, 0.91 times as long as wide. Spermatheca (Fig. 1J) ellipsoidal, 1.7 times as long as its greatest width, well sclerotized except duct and small area near juncture with duct unsclerotized, and with hexagonal pattern on surface; internal setae absent; both accessory ducts slender, subequal in diameter to major one.
Male. Body length 4.3 mm. Head somewhat wider than thorax. Upper eye yellowish brown, consisting of 13 vertical columns and 16 horizontal rows of large facets. Face grayish-black, grayish-white pruinose. Clypeus brownish black, whitish pruinose, densely covered with golden-yellow scale-like medium-long hairs (directed upward and lateral) interspersed with several dark brown simple longer hairs. Antenna composed of scape, pedicel and 9 flagellomeres, yellow to brown; 1 st flagellomere elongate, 1.63 times as long as 2 nd one. Maxillary palp light to medium brown, with 5 segments, proportional lengths of 3 rd, 4 th, and 5 th segments 1.00:1.57:3.21; 3 rd segment (Fig. 2A) widened apically; sensory vesicle (Fig. 2A) ellipsoidal, small (0.27 times as long as 3 rd segment), and with small opening. Thorax. Scutum slightly darker than female and short hairs on scutum golden yellow. Foreleg: coxa yellow; trochanter yellow with some portions light brown; femur light brown except apical cap brown; tibia brown with median 2/3 light brown and covered with dark brown hairs; tarsus brown to dark brown; basitarsus moderately dilated 6.2 times as long as its greatest width. Midleg: coxa yellowish brown; trochanter yellow to brown; femur yellow except apical 1/4 brown; tibia medium brown to dark brown; tarsus dark brown to brownish-black except anterior surface of little less than basal 1/2 of basitarsus dark yellow to light brown. Hindleg: coxa dark yellow to brown; trochanter yellow; femur light brown except apical 1/2 dark brown; tibia (Fig. 2B) brown except basal and apical portion dark brown; tarsus medium to dark brown except basal 1/2 (or little less) of basitarsus whitish-yellow and little less than basal 1/3 of 2 nd tarsomere white; basitarsus (Fig. 2C) slender, spindle-shaped, 4.2 times as long as wide, and 0.68 and 0.77 times as wide as greatest width of tibia and femur, respectively; calcipala (Fig. 2C) nearly as long as wide, and 0.32 times as wide as greatest width of basitarsus. Pedisulcus (Fig. 2C) well defined. Wing. Length 2.4 mm. Costa with dark brown spinules as well as dark brown hairs except basal portion with patch of yellowish hairs. Subcosta bare. Hair tuft on stem vein dark brown. Basal portion of radius fully haired; R1with dark spinules and hairs and R2 with hairs only. Basal cell absent. Halter. Yellowish brown except outer surface ochreous, basal stem darkened and apex white. Abdomen. Basal scale dark brown, with fringe of light to medium brown hairs. Dorsal surface of abdomen dark brown except segment 2 light brown (though posterior 1/4 of dorsal surface brown), covered with dark brown short to long hairs; segments 2, 5–7 with shiny dorsolateral or lateral patches; ventral surface of segment 2 yellow, those of segments 3 and 4 yellow except sternites medium brown, and those of other segments medium to dark brown. Genitalia. Coxite in ventral view (Fig. 2D) nearly rectangle, 1.5 times as long as its greatest width. Style in ventral view (Fig. 2D) slightly bent inward, slightly tapered from base to apex, sharped apically and with apical spine; style in medial view (Fig. 2E) longer than coxite (0.75 times as long as coxite), gently bent inward, nearly parallel-sided, with apical spine; style in ventro-lateral view (Fig. 2F) very slightly tapered toward apical 3/4, with rounded apex. Ventral plate in ventral view (Fig. 2D) with body broad, 0.81 times as long as wide, tapered posteriorly, with anterior margin produced antero-medially, and posterior margin concave medially, densely covered with microsetae on ventral surface; basal arms of long, directed forward, then convergent apically; ventral plate in lateral view (Fig. 2G) moderately produced ventrally; ventral plate in end view (Fig. 2H) body and ventrally-produced median process nearly equilateral triangular. Median sclerite (Fig. 2G) thin, plate-like, wide. Paramere (Fig. 2I) of moderate size, with 3 distinct long, stout hooks plus several smaller ones. Aedeagal membrane moderately setose, slightly sclerotized at base but dorsal plate not well defined. Ventral surface of abdominal segment 10 without distinct hairs near posterior margin. Cercus in lateral view (Fig. 2J) small, rounded, with 3–5 hairs.
Pupa (n =7). Body length 3.1–3.3 mm. Head. Integument dark yellow, moderately covered with small round tubercles; antennal sheath with protuberance; face with pair of simple very long trichomes with uncoiled apices, and frons with 3 pairs of simple very long trichomes with coiled or uncoiled apices; 2 frontal trichomes on each side arising close together, subequal in length to one another and slightly longer than facial one. Thorax. Integument yellow, covered with round tubercles, with 3 simple very long dorsomedial trichomes with coiled apices, 1 simple very long anterolateral trichome with coiled apices, 1 simple very long mediolateral trichome with uncoiled apex, and 3 simple ventrolateral trichome with uncoiled apices (1 medium-long and 2 short) on each side. Gill (Fig. 3A) composed of 8 slender thread-like filaments, arranged as [(1 + 2) + (1 + 2)] + 2 filaments from dorsal to ventral, with short common basal stalk having somewhat swollen transparent organ ventrally at base; common basal stalk 0.41 times length of interspiracular trunk; dorsal and middle triplet sharing short common stalk; primary stalks of dorsal slightly shorter than middle triplet, but the secondary stalk of dorsal triplet medium-long; primary stalk of middle triplet shorter than stalk of ventral pair, but the secondary stalk of middle triplet long; stalk of ventral pair medium-long, 0.8–0.9 times length of common basal stalk and 0.38–0.40 times length of interspiracular trunk; stalk of ventral pair 1.1–1.31 times as thick as primary stalk of middle triplet, and 1.05 times as thick as primary stalk of dorsal triplet; primary stalk of dorsal triplet lying against stalk of ventral pair at angle of 80–90 degrees or little more when viewed laterally; all filaments yellowish brown, gradually tapered toward apex; entire length of filaments (measured from base of gill to tips of filaments) based on one pupa as follows: 1.9–2.1 mm for dorsal triplet, 2.1–2.3 mm for middle triplet and 3.2–3.4 mm for ventral paired filaments; cuticle of all filaments with welldefined annular ridges and furrows though gradually becoming indistinct from middle to apex, densely covered with minute tubercles. Abdomen. Dorsally, segments 1 and 2 brownish yellow and with tubercles; segment 1 with 1 simple slender medium-long hair-like seta on each side; segment 2 with 1 simple medium-long and 3 short hair like setae on each side; segments 3 and 4 each with 4 hooked spines and 1 short hair like seta on each side; segment 5 lacking spine–combs and 1 short hair-like seta on each side; segments 6–9 each with spine-combs in transverse row (though those on segment 9 slightly smaller than those on segment 8) and comb-like groups of minute spines on each side; segment 9 with pair of triangular flat terminal hooks, of which outer margin slightly longer than inner margin and not crenulated (Fig. 3B). Cocoon. Wall-pocket-shaped, thinly and moderately woven, anterior margin somewhat thickly woven, with dorsal portion slightly produced anteriorly when viewed dorsally; posterior 1/2 with floor roughly or moderately woven; individual threads visible; 3.5 mm long by 2.8 mm wide.
Mature larva (n =12). Body length 5.3–5.6 mm. Body creamy to colored with markings as follows: thoracic segment 1 encircled with ochreous broad transverse band (not continuous ventrally), proleg grayish, thoracic segments 2 and 3 grayish dorsally and each with distinct ochreous wide areas ventrally, abdominal segments 1–4 each encircled with yellowish brown broad band, abdominal segments 5–8 almost entirely covered by yellowish brown transverse broad band on dorsal and dorsolateral surfaces; abdominal segments 5 and 6 each with W-shaped broad transverse grayish-brown band on dorsolateral surfaces of posterior 1/2 of each segment; abdominal segment 7 and 8 with transverse yellowish brown band on ventral surface; Cephalic apotome yellowish brown, and sparsely covered with simple minute setae; head spots indistinct. Lateral surface of head capsule yellowish brown except eye-spot region yellow, and very sparsely covered with simple minute setae; spots indistinct. Ventral surface of head capsule yellowish brown except somewhat darkened area near posterior margin on each side of postgenal cleft, and very sparsely covered with simple minute setae. Antenna composed of 3 articles and apical sensillum, 1.2 times longer than stem of labral fan; proportional lengths of 1 st, 2 nd, and 3 rd segments 1.0:1.1:09.1.30. Labral fan with 34 main rays. Mandible (Fig. 3C) with 3 comb-teeth decreasing in length from 1 st to 3 rd; mandibular serrations composed of 2 teeth (1 medium-sized and 1 small); major tooth at acute angle against mandible on apical side; supernumerary serrations absent. Hypostoma (Fig. 3D) with row of 9 apical teeth; median and each corner tooth prominent (though median tooth slightly longer than corner teeth) and much longer than 3 intermediate teeth on each side; lateral margin smooth; 4 hypostomal bristles per side arrayed parallel to lateral margin. Postgenal cleft (Fig. 3E) arrow-headshaped, 4.1 times as long as postgenal bridge. Cervical sclerite composed of 2 very pale small pieces, not fused to occiput, moderately separated medially from each other. Thoracic cuticle finely covered with minute dark spinules. Abdominal cuticle almost bare except few posterior segments sparsely to moderately covered with simple minute setae dorsally and dorsolaterally and last segment densely covered with colorless simple setae on each side of anal sclerite. Rectal scales absent. Rectal papilla compound, each of 3 lobes with 5 finger-like secondary lobules. Anal sclerite of usual X-form, with anterior arms little shorter (0.75 times as long as posterior arms) than posterior ones, broadly sclerotized at base; accessory sclerite absent. Last abdominal segment expanded ventrolaterally forming double bulges on each side, visible as large conical ventral papilla when viewed from side. Posterior circlet with 56 rows of hooklets with up to 14–16 hooklets per row.
Etymology. The species is name dinakarani is in honor of Professor S. Dinakaran, Department of Zoology, The Madura College, Madurai, who contributed many works on aquatic insects from India.
Type series. Holotype, Female (preserved in ethanol), reared from a pupa, collected from a fast-flowing stream (width 5–12 m, depth 5–20 cm, bedrock stream, water temperature 19.7°C, exposed to the sun, altitude 1186 m, 10°26’90.73’’N/ 77°61’15.78’’E), stream at Moolayar, Palani hills of Southern Western Ghats, Tamil Nadu, India, 10-II-2017, by S. Anbalagan & S. Vijayan; Paratype, 6 females, 8 males, 20 pupae and 30 mature larvae, same data as the holotype, holotype and paratypes deposited in deposited in CRAE (No: SGB005).
Habitat. The pupae and larvae of this new species were collected from leaves and grasses trailing in the water. The associated species were Teloganodes kodai, Hydropsyche sp.
description: Published as part of Anbalagan, Sankarappan, Vijayan, Suruliyandi, Balachandran, Chellapandian, Thiyonila, Berchmans & Surya, Aathmanathan, 2020, Two new species of Simulium (Gomphostilbia) (Diptera: Simuliidae) from South India, pp. 57-72 in Zootaxa 4742 (1) on pages 58-64, DOI: 10.11646/zootaxa.4742.1.3, http://zenodo.org/record/3674463