Simulium (Simulium) chamlongi Takaoka & Suzuki, 1984

Takaoka, Hiroyuki, Sofian-Azirun, Mohd, Ya’Cob, Zubaidah, Chen, Chee Dhang, Lau, Koon Weng, Low, Van Lun, Pham, Xuan Da & Adler, Peter H., 2017, The black flies (Diptera: Simuliidae) of Vietnam, Zootaxa 4261 (1), pp. 1-165 : 154-160

Simulium (Simulium) chamlongi Takaoka & Suzuki, 1984

Simulium (Simulium) chamlongi Takaoka & Suzuki, 1984: 27 –30 (Female, male, pupa and larva); Crosskey and Howard, 1997; Pham, 1999: 335; Takaoka et al., 2015a: 93 .

Distribution. Thailand and Vietnam (Bac Thai and Lam Dong).

Remarks. This species was originally described from Thailand by Takaoka and Suzuki (1984) and later recorded from Vietnam by Crosskey and Howard (1997), Pham (1999) and Takaoka et al. (2015a). No detailed information for the locality was given by Crosskey and Howard (1997).

Simulium (Simulium) phuluense Takaoka & Sofian-Azirun sp. nov.

Female. Body length 2.6–3.1 mm. Head. Narrower than thorax. Frons black, shiny, with several dark long stout hairs along each lateral margin and three to five similar hairs on each side just above lower margin; frontal ratio 1.3:1.0:1.2–1.4; frons:head ratio 1.0:3.6–4.3. Fronto-ocular area well developed, short, directed laterally and slightly upward. Clypeus black, white pruinose, slightly shiny when illuminated at certain angles, moderately covered with dark-brown long stout hairs except mediolongitudinal area of upper half somewhat widely bare. Labrum 0.7 times as long as clypeus. Antenna composed of scape, pedicel and nine flagellomeres, medium to dark brown except scape, pedicel and base of first flagellomere yellow when viewed dorsally, and scape, pedicel and basal four-fifths of flagellomere yellow when viewed ventrally. Maxillary palp with five segments, grayish brown except segments 1 and 2 yellow; proportional lengths of third, fourth, and fifth segments 1.0:1.3:2.8–3.1; third segment ( Fig. 69 A) of normal size; sensory vesicle ( Fig. 69 A) of moderate size, (0.3–0.4 times length of third segment) having opening of moderate size. Maxillary lacinia with 13 or 14 inner and 16 or 17 outer teeth. Mandible with 30–32 inner and 16 outer teeth. Cibarium ( Fig. 69 B) with blunt medial projection on posterior margin and with about 30 small pointed processes and about 28 minute ones near base of medial projection. Thorax. Scutum black, white pruinose along lateral margins, shiny when illuminated at certain angles, densely covered with goldenyellow recumbent short hairs interspersed with several dark-brown long upright hairs on prescutellar area. Scutellum dark brown, covered with dark-brown upright long hairs and golden-yellow short hairs. Postnotum brownish black, white pruinose when illuminated at certain angles and bare. Pleural membrane bare. Katepisternum longer than deep, brownish black, shiny and white pruinose when illuminated at certain angles and bare. Legs. Foreleg: coxa whitish yellow; trochanter yellow; femur yellow except apical cap light brown; tibia yellowish white except basal one-fourth light brown and apical cap brownish black, with shiny sheen widely on outer surface when illuminated at certain angles; tarsus brownish black, with moderate dorsal hair crest; basitarsus greatly dilated, 5.6–5.8 times as long as its greatest width. Midleg: coxa brownish black; trochanter yellow; femur yellow with apical cap light brown; tibia ( Fig. 69 C) whitish yellow to dark yellow except apical cap medium brown and narrow portion of outer surface along posterior margin widely light to medium brown, and with shiny sheen on posterior surface when illuminated at certain angles; tarsus medium brown except basal half to two-thirds of basitarsus yellow. Hind leg: coxa dark brown; trochanter yellow; femur yellow with apical cap medium brown; tibia ( Fig. 69 D) yellow on little less than basal half, and gradually darkened toward apex and apical cap dark brown on outer and posterior surface, and widely yellow except apical cap dark brown on inner surface, with shiny sheen on posterior surface when illuminated at certain angles; tarsus medium brown except basal two-thirds of basitarsus and basal half of second tarsomere yellow; basitarsus ( Fig. 69 E) nearly parallel-sided, 6.2–6.3 times as long as wide, and 0.7–0.8 and 0.6–0.7 times as wide as greatest widths of hind tibia and femur, respectively; calcipala ( Fig. 69 E) moderately developed, slightly shorter than basal width, and 0.5 times as wide as basitarsus; pedisulcus ( Fig. 69 E) well developed; claw ( Fig. 69 F) with small subbasal tooth. Wing. Length 2.7–3.1 mm. Costa with dark spinules and hairs; subcosta haired except near apex bare; basal section of radius bare; R1 with dark spinules and hairs; R2 with hairs; hair tuft on base of radial vein dark brown; basal cell absent. Halter . White with basal portion darkened. Abdomen. Basal scale light brown, with fringe of pale long hairs. Dorsal surface of abdomen medium brown except segment 2 light brown, with short dark hairs; tergite 2 shiny, white iridescent when illuminated at certain angles, and tergites 6–8 shiny; ventral surface of segment 2 whitish and those of others light brown; segment 7 with median large sternal plate having numerous hairs. Terminalia . Sternite 8 ( Fig. 69 G) bare medially, with 22–25 dark medium-long to long stout hairs on each lateral surface. Ovipositor valves ( Fig. 69 G) wide, with inner margins widely concave, with posteromedial apices pointed anteriorly, each moderately covered with microsetae and 35 or 36 short to medium-long hairs except small area of posteromedial apex bare; inner margins widely concave and darkened except near apex unpigmented. Genital fork ( Fig. 69 H) of inverted-Y form, with narrow, well sclerotized stem; arms of moderate width, each with distinct short projection directed anterodorsally. Paraproct in ventral view ( Fig. 69 I) oblong, widely depressed on ventral surface, unpigmented except medial surface somewhat darkened, sparsely covered with minute setae and sensilla; paraproct in lateral view ( Fig. 69 J) much protruded ventrally beyond ventral margin of cercus, 0.7 times as long as wide, with numerous short to medium-long hairs on lateral and ventral surfaces; anteromedial surface with 10 or 11 short sensilla. Cercus in lateral view ( Fig. 69 J) short, trapezoid, 0.48 times as long as wide, and with numerous short to medium-long hairs. Spermatheca ( Fig. 69 K) large, nearly ovoid, 1.3 times as long as wide, well sclerotized except portion of juncture with duct unsclerotized, with no defined surface patterns, and with internal setae; accessory ducts subequal in thickness to each other, and to major duct.

Male. Body length 3.0– 3.3 mm. Head. Nearly as wide as thorax. Upper eye medium brown, consisting of large facets in 23 or 24 vertical columns and in 23 or 24 horizontal rows. Clypeus black, thickly white pruinose, moderately covered with dark-brown hairs. Antenna composed of scape, pedicel and nine flagellomeres, dark brown except base of first flagellomere light brown; first flagellomere elongate, 1.6 times as long as second one. Maxillary palp medium brown, composed of five segments with proportional lengths of third, fourth, and fifth segments 1.0:1.2:2.5; third segment ( Fig. 70 A) of moderate size, with apex somewhat produced inward; sensory vesicle ( Fig. 70 A) small (0.2 times length of third segment), ellipsoidal, and with small opening. Thorax. Nearly as in male of S. (S.) daoense sp. nov. Legs. Foreleg: coxa yellow; trochanter light brown; femur light to medium brown with apical cap dark brown; tibia brownish black except middle one-third medium brown, though outer surface widely white except basal tip and apical cap, and with white sheen when illuminated at certain angles; tarsus brownish black, with moderate dorsal hair crest; basitarsus moderately dilated, 6.7–7.7 times as long as its greatest width. Midleg: dark brown to brownish black except extreme base of tibia whitish yellow and basal half of basitarsus yellow. Hind leg: coxa brownish black; trochanter light brown; femur medium brown except base light brown or dark yellow and apical cap brownish black; tibia dark brown to brownish black except basal tip whitish yellow; tarsus ( Fig. 70 B) medium brown except basal half to two-fifths of basitarsus yellow (though base somewhat darkened) and little less than basal half of second tarsomere yellow; basitarsus ( Fig. 70 B) much enlarged, spindle-shaped, gradually widened from base to apical one-third, then tapered to apex, 4.3 times as long as its greatest width, and 0.8 and 0.9–1.0 times as wide as greatest widths of hind tibia and femur, respectively; calcipala ( Fig. 70 B) small, slightly shorter than width at base, 0.3 times as wide as greatest width of basitarsus; pedisulcus ( Fig. 70 B) well developed. Wing. Length 2.7–2.9 mm. Other characters as in female including subcosta with 12–24 hairs though apical one-fifth and one-third bare. Halter . White with basal portion darkened. Abdomen. Basal scale dark brown to brownish black, with fringe of dark long hairs. Dorsal surface of abdomen dark brown to brownish black, and covered with dark short hairs; segments 2 and 5–7 each with pair of silvery or bluish iridescent spots dorsolaterally, those on segment 2 broadly connected in middle to each other. Genitalia. Coxites, styles and ventral plate in ventral view as Fig. 70 C. Coxite in ventral view nearly quadrate, 1.2 times as long as width. Style in ventrolateral view ( Fig. 70 D) elongate, 3.48 times as long as its greatest width near base, slightly tapered to apex; style in medial view ( Fig. 70 E) 1.6 times as long as coxite, spatulate dorsoventrally except basal half much produced dorsally in form of isosceles triangular. Ventral plate in ventral view ( Fig. 70 C) Y-shaped, body with several teeth on each side of posterior surface, and with ventrally produced process covered with several minute setae on its ventroposterior surface; arms widely divergent basally and convergent apically; ventral plate in lateral view ( Fig. 70 F): body with serrated posterior margin, and sparsely covered with minute setae on each anterolateral surface, and having ventrally produced process with anterolateral surface bare except several minute setae near base; arm wide with apex curved ventrally; ventral plate in caudal view ( Fig. 70 G): body and ventrally produced process gradually tapered ventrally, with round apex, having seven to nine teeth on each side of posterior surface, and several minute setae on posterior surface of ventrally produced process. Median sclerite ( Fig. 70 F, H) arising near anterior margin of ventral plate and directed dorsally, plate-like, widened from base toward apical one-third, then nearly parallel-sided or slightly narrowed toward apex, brown basally, but not so well sclerotized apically. Paramere ( Fig. 70 I) broad basally, with several long hooks and shorter ones. Aedeagal membrane ( Fig. 70 J) densely covered with minute setae, and with partially sclerotized dorsal plate in form of horizontal bar ( Fig. 70 K). Abdominal segment 10 ( Fig. 70 L, M) without distinct hair on ventral and lateral surfaces. Cercus ( Fig. 70 L, M) small, rounded, with 14–16 distinct hairs.

Pupa. Body length 2.7–3.2 mm. Head. Integument yellow to ochreous, moderately covered with small round tubercles except antennal sheath bare; frons with pair of unbranched slender short trichomes ( Fig. 71 A) on each side; face with unbranched slender short trichome ( Fig. 71 B) on each side. Thorax. Integument yellow to ochreous, moderately covered with small round tubercles; thorax with two long anterodorsal trichomes ( Fig. 71 C), two anterolateral trichomes (anterior trichome medium-long, and posterior trichome long) ( Fig. 71 D), one mediumlong mediolateral trichome ( Fig. 71 E), and three ventrolateral trichomes (one short, two others medium-long) ( Fig. 71 F), on each side; all unbranched and with straight apices. Gill ( Fig. 71 G) with six slender thread-like short filaments in three pairs; all pairs short-stalked, arising from short common basal stalk; gill filaments divergent basally, upper filament of dorsal pair lying at angle of 120 degrees against lower filament of ventral pair when viewed laterally; filaments subequal in length to one another (2.2–2.4 mm long) (though lower filament of middle pair and upper filament of ventral pair somewhat longer (2.7 mm long); relative thickness of six filaments from dorsal to ventral when basal portions were compared 1.0:0.9:1.0:1.0:0.8:0.8; all filaments light to medium brown, tapered toward apex, with distinct annular ridges and furrows forming definite reticulate surface patterns, and densely covered with minute tubercles (relatively larger ones on ridges). Abdomen. Dorsally, segment 1 and basal half of segment 2 light brown and without minute tubercles, and other segments unpigmented except segment 9 and basal portions of spine-combs on segments 7 and 8 yellow; segment 1 with one unbranched slender short seta ( Fig. 71 H) on each side; segment 2 with one unbranched slender short seta and five unbranched short setae, of which four are stout ( Fig. 71 I), on each side; segments 3 and 4 each with four distinct hooked spines and one unbranched short seta on each side; segments 7 and 8 each with distinct spine-combs in transverse row on each side; segments 5, 6 and 9 lacking spine-combs; segments 6–9 each with comb-like groups of minute spines on each side; segment 9 with cone-shaped terminal hooks ( Fig. 71 J). Ventrally, segments 3–9 unpigmented, each (except segment 9) with comb-like groups of minute spines; segment 4 with one unbranched slender minute seta, two stout hooklets ( Fig. 71 K) on each side; segment 5 with pair of bifid stout hooks submedially and few unbranched short setae on each side; segments 6 and 7 each with pair of bifid inner and unbranched outer stout hooks somewhat separated from each other, and few unbranched short setae on each side. Grapnel-shaped hooklets absent on each side of segment 9. Cocoon. Wall-pocket-shaped, tightly and thickly woven, ochreous, not so extended ventrolaterally; individual threads invisible; 3.5–4.5 mm long by 1.6–2.2 mm wide.

Mature larva. Body length 7.4–8.4 mm. Body whitish to light grayish, and thoracic segment 1 encircled with pinkish to reddish-brown transverse band though disconnected ventromedially, and other thoracic segments and abdominal segments pinkish to light ochreous dorsally to varying extent. Head. Cephalic apotome yellowish white to yellow with somewhat darkened narrow area along posterior margin; head spots faintly positive though anterior spot of mediolongitudinal spots often less distinct; lateral surface of head capsule yellow except eye-spot region yellowish white and eyebrow darkened and area between eye-spot region and posterior margin always darkened though spots in front of posterior margin obscured or faintly negative; one small spot below eye-spot region indistinct; ventral surface of head capsule ( Fig. 72 A) yellow to light brown, with spots on each side of postgenal cleft obscured or faintly negative. Head capsule sparsely covered with minute setae on dorsal, lateral and ventral surfaces. Antenna composed of three articles and apical sensillum, slightly longer than stem of labral fan; length ratio of three articles (from base to tip) 1.0:1.1–1.2:0.6–0.7. Labral fan with 49–51 primary rays. Mandible ( Fig. 72 B) with mandibular serration composed of two teeth (one medium-sized, one small); main tooth at obtuse angle against mandible on apical side; supernumerary serrations absent; comb-teeth decreasing in length from first to third. Hypostoma ( Fig. 72 C) with nine anterior teeth, of which corner teeth slightly longer than median tooth; three intermediate teeth on each side shortest; lateral margins moderately serrate apically; six hypostomal bristles per side divergent posteriorly from lateral margin. Postgenal cleft ( Fig. 72 A) medium-sized, 2.1 times as long as postgenal bridge, pointed apically; sheath of subesophageal ganglion usually weakly pigmented, wine-glassshaped, or not pigmented. Cervical sclerites on each side composed of anterior dark slender rod-like piece and posterior dark elliptical piece close together, and not fused to occiput. Thorax and Abdomen. Histoblast of pharate pupal gill with six thread-like filaments. Thoracic and abdominal cuticle bare except last segment of abdomen moderately covered with short colorless setae on each side of anal sclerite. Rectal scales present. Rectal organ compound, each lobe with 18–21 finger-like secondary lobules. Anal sclerite X-shaped, with short broad anterior arms with forked apices, 0.8 times as long as posterior ones; no or one sensillum on base of anal sclerite; four to nine sensilla posterior to posterior arms. Last abdominal segment lacking ventral papillae. Posterior circlet with 88–95 rows of hooklets with up to 13 or 14 hooklets per row.

Type material. HOLOTYPE: Female (with its associated pupal exuviae and cocoon) in 80% ethanol, labeled in a vial as [ UMSRP: Vietnam 0 46, Holotype, Simulium (S.) phuluense , Female, coll. Vietnam, 23-XII-2014, Takaoka et al.], reared from a pupa collected from a small shallow stream (width 2.0 m, depth 15 cm, bottom of pebbles, water temperature 9.0˚C, partially shaded, elevation 1,192 m, 22˚23’03.208”N/103˚50’58.990”E) moderately flowing in a natural forest, Sapa , Lao Cai Province, northern Vietnam , 23-XII-2014, by H. Takaoka, M. Sofian-Azirun, Z. Ya’cob, C.D. Chen & K.W. Lau. PARATYPES: Three females, four males (all reared from pupae) and five mature larvae in 80% ethanol, same data as those of the holotype, labeled in each vial as [ UMSRP: Vietnam 0 46, Paratype, Simulium (S.) phuluense , coll. Vietnam, 23-XII-2014, Takaoka et al.].

Biological notes. The pupae and larvae of S. (S.) phuluense sp. nov. were collected from grass leaves and roots trailing in the current. This species is one of the dominant species in Sapa, being found in 12 of 23 streams surveyed. Associated species were S. (G.) hongthaii , S. (S.) daoense sp. nov., S. (S.) doipuiense (complex) and S. (S.) sapaense sp. nov.

Distribution. Vietnam (Lao Cai).

Etymology. The species name phuluense refers to the land in which the tribe Phulu lives.

Remarks. Simulium (S.) phuluense sp. nov. is assigned to the S. variegatum species-group of the subgenus Simulium , redefined by Takaoka (2003), based on the pleural membrane bare, female claw with a small subbasal tooth ( Fig. 69 F), ovipositor valves with inner margins widely concave ( Fig. 69 G), male style without basal protuberance ( Fig. 70 E), pupal gill with six filaments ( Fig. 71 G).

This new species is characterized by a greater number of the upper-eye facets in 23 or 24 vertical columns and 23 or 24 horizontal rows, and haired subcosta in the male. No other related species of the S. variegatum speciesgroup have such a combination of characters except S. (S.) oitanum (Shiraki) (reported as S. (Odagmia) aokii ) from Koshiki Island, Nansei Islands, Japan, which has the male subcosta with 10–12 hairs, although it has the male upper-eye facets in about 16 horizontal rows ( Takaoka 1976). Simulium (S.) zunyiense Chen, Xiu & Zhang , from Guizhou Province, China, has a similar greater number of male upper-eye facets (in 22 vertical columns and 26 horizontal rows), but differs by having a bare male subcosta, style with a short subbasal protuberance, and triangular larval postgenal cleft ( Chen et al. 2012). The females of S. (S.) jingfui Cai, An & Li described from a female and a male from Sichuan Province, China, and S. (S.) liubaense Liu & An described from a female from Shaanxi Province, China, differ by having dark fore coxa, and an ovipositor valve rounded apically ( Cai et al. 2008; Liu and An 2009).

Figures

FIGURE 69. Female of Simulium (Simulium) phuluense sp. nov. A, Third segment of maxillary palp with sensory vesicle (right side; front view); B, Cibarium (front view); C, Fore tibia (left side; outer view); D, Hind tibia (left side; outer view); E, Hind basitarsus and second tarsomere (left side; outer view). F, Claw; G, Sternite 8 and ovipositor valve (right side only; ventral view); H, Genital fork (ventral view); I & J, Paraprocts and cerci (I, ventral view; J, lateral view). K, Spermatheca. Scale bars. 0.1 mm for C – E; 0.02 mm for A, B and F – K.

FIGURE 70. Male of Simulium (Simulium) phuluense sp. nov. A, Third segment of maxillary palp with sensory vesicle (right side; front view); B, Hind basitarsus and second tarsomere (left side; outer view); C, Coxites, styles and ventral plate (ventral view); D & E, Styles (D, right side and ventrolateral view; E, left side and medial view); F, Ventral plate and median sclerite (lateral view); G, Ventral plate (caudal view); H, Median sclerite (caudal view); I, Paramere (right side; caudal view); J, Aedeagal membrane (right half; caudal view); K, Dorsal plate (caudal view); L & M, Abdominal segment 10 and cerci (right side; L, lateral view; M, caudal view). Scale bars. 0.1 mm for B; 0.02 mm for A and C – M.

FIGURE 71. Pupa of Simulium (Simulium) phuluense sp. nov. A, Frontal trichomes; B, Facial trichome; C – F, Thoracic trichomes (C, anterodorsal; D anterolateral; E, mediolateral; F ventrolateral); G, Anterior part of thorax and gill filaments (right side; outer view); H, Hair-like seta on dorsal surface of abdominal segment 1; I, Hair-like seta, minute seta and stout seta on dorsal surface of abdominal segment 2; J, Terminal hooks (caudal view); K, Hooklets and short seta on ventral surface of abdominal segment 4. Scale bars. 0.1 mm for G; 0.02 mm for A – F and H – J.

FIGURE 72. Larva of Simulium (Simulium) phuluense sp. nov. A, Head capsule (ventral view); B, Mandible; C, Hypostoma. Scale bars. 0.1 mm for A; 0.04 mm for C; 0.02 mm for B.