Simulium (Gomphostilbia) namdanense Takaoka, Srisuka & Saeung, 2020
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publication ID |
https://dx.doi.org/10.3897/zookeys.950.51298 |
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publication LSID |
lsid:zoobank.org:pub:3E805885-D335-4FB3-AE8D-FA443FAD82AE |
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persistent identifier |
https://treatment.plazi.org/id/DA8262B8-729B-4579-B4FC-218F4A476899 |
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taxon LSID |
lsid:zoobank.org:act:DA8262B8-729B-4579-B4FC-218F4A476899 |
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scientific name |
Simulium (Gomphostilbia) namdanense Takaoka, Srisuka & Saeung |
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sp. nov. |
Simulium (Gomphostilbia) namdanense Takaoka, Srisuka & Saeung sp. nov. Figs 23 View Figure 23 , 25F View Figure 25
Material examined.
Holotype: Male (with its associated pupal exuviae and cocoon) (in 80% ethanol) labeled as "Holotype: Simulium namdanense male, QSBG col. no. 59, Thailand, 25-VII-2017, by W. Srisuka", collected from a medium-sized stream of Nam Khwang (width 4 m, depth 30 cm, bed sandy, fast flow, pH 7.2, 19.5 °C, partially shaded, elevation 1,192 m, 19°11'18.3"N, 101°04'43.7"E), at Nam Dan Village, Pua District, Nan Province, Thailand, 25-VII-2017, by W. Srisuka (Coll. No. 59).
Paratypes: Three females, two males (with their associated pupal exuviae and cocoons), and five mature larvae (in 80% ethanol), same data as for holotype; two females, four males (thorax of one male for DNA analysis) (with their associated pupal exuviae and cocoons), and two mature larvae (one mature larva for DNA analysis) (in 80% ethanol), collected from a medium-sized stream (width 3 m, depth 32 cm, bed sandy and rocky, moderate flow, pH 6.5, 23.2 °C, partially shaded, elevation 503 m, 18°48'44.2"N, 98°56'21.3"E), at Huai Kaew Waterfall, Doi Suthep, Muang District, Chiang Mai Province, Thailand, 30-VII-2017, by W. Srisuka (Coll. No. 94).
Diagnosis.
Female: elongate sensory vesicle (Fig. 23A View Figure 23 ). Male: higher number of upper-eye facets in 15 or 16 vertical columns and 16 or 17 horizontal rows, and hind basitarsus (Fig. 23D View Figure 23 ) spindle-shaped, narrower than the hind tibia and femur. Pupa: small terminal hooks (Fig. 23K View Figure 23 ). Larva: postgenal cleft 2.5 times as long as the postgenal bridge (Fig. 23L View Figure 23 ) and abdominal segments 1-4 each encircled with a light greyish band (Fig. 25F View Figure 25 ).
Description.
Female (N = 5). Body length 1.8-2.0 mm.
Head. Frons dark brown, densely covered with yellowish white scale-like recumbent short hairs (no dark longer hairs); frontal ratio 1.8-1.9:1.0:2.2-2.4; frons:head ratio 1.0:4.0-4.1. Labrum 0.59-0.63 times length of clypeus. Maxillary palpus: proportional lengths of third, fourth, and fifth palpal segments 1.0:0.9:1.9-2.0; sensory vesicle (Fig. 23A View Figure 23 ) elongate, (0.64-0.68 times length of third palpal segment), with medium-sized opening. Lacinia with 13 or 14 inner and 16-21 outer teeth. Mandible with 30-32 inner teeth and three to five outer teeth at some distance from tip.
Legs. Foreleg: trochanter light brown; basitarsus moderately dilated, 5.7-5.8 times as long as its greatest width. Midleg: trochanter dark yellow to light brown. Hind leg: coxa light brown; tibia yellowish white on basal half or little more and light brown to brownish black on rest; basitarsus yellowish white except base and little less than apical one-third dark brown, 6.1-6.4 times as long as wide, and 0.7 and 0.5-0.6 times as wide as greatest widths of tibia and femur, respectively; calcipala nearly as long as width at base, and 0.45-0.56 times as wide as greatest width of basitarsus; claw with large basal tooth 0.47-0.52 times length of claw.
Wing. Length 2.0 mm.
Abdomen. Dorsal surface of abdomen medium to dark brown except most of segment 2 (except narrow portion along posterior margin darkened) ochreous.
Terminalia. Sternite 8 with 18-26 medium-long to long hairs together with two or three slender short hairs on each side. Ovipositor valve moderately covered with microsetae interspersed with two to four short hairs. Genital fork (Fig. 23C View Figure 23 ) with inner margins of arms divergent from each other (not convergent posteriorly). Paraproct with four or five sensilla on anteromedial surface, 0.5 times as long as wide when viewed laterally, and with 20-23 short long hairs on ventral and lateral surfaces. Cercus in lateral view 0.44 times as long as wide. Spermatheca 1.55 times as long as its greatest width; both accessory ducts slender, subequal in diameter to each other and slightly thicker than major one.
Male (N = 7). Body length 2.0 mm.
Head. Slightly wider than thorax. Upper eye medium brown, consisting of large facets in 15 or 16 vertical columns and 16 or 17 horizontal rows on each side. Antenna: first flagellomere elongate, 1.6-1.8 times length of second. Maxillary palpus light brown, with five palpal segments, proportional lengths of third, fourth, and fifth palpal segments 1.0:1.1-1.3:2.7; third palpomere (Fig. 23B View Figure 23 ) somewhat enlarged; sensory vesicle (Fig. 23B View Figure 23 ) medium sized, ellipsoidal (0.33 times length of third palpal segment).
Legs. Foreleg: femur light brown except apical cap medium brown (though apical tip yellowish); tibia light brown except median large portion of outer surface whitish and little less than apical one-third dark brown; basitarsus moderately dilated, 6.5-6.9 times as long as its greatest width. Hind leg: coxa light to medium brown; trochanter whitish yellow; femur light to medium brown with base whitish yellow and apical cap dark brown (though apical tip yellow); tibia dark brown to brownish black except little less than basal half yellow; tarsus (Fig. 23D View Figure 23 ) dark brown except little less than basal half of basitarsus (though its border not well defined due to covering of dark hairs throughout its length) greyish white and basal half of second tarsomere yellow; basitarsus (Fig. 23D View Figure 23 ) 4.2-4.4 times as long as wide, and 0.8 and 0.8-0.9 times as wide as greatest width of tibia and femur, respectively; calcipala (Fig. 23D View Figure 23 ) as long as basal width, and 0.32 times as wide as greatest width of basitarsus.
Wing. Length 1.8-1.9 mm. Subcosta bare or with one to three hairs.
Genitalia. Coxite in ventral view (Fig. 23E View Figure 23 ) 1.6 times as long as its greatest width. Style in ventral view (Fig. 23E View Figure 23 ) with round apex; style in ventrolateral view (Fig. 23F, G View Figure 23 ) slightly tapered or parallel-sided from middle toward apex, with round apex. Ventral plate in ventral view (Fig. 23E View Figure 23 ) 0.54 times as long as wide; basal arms nearly parallel-sided, then convergent apically; ventral plate in caudal view (Fig. 23I View Figure 23 ) trapezoidal, though ventral margin slightly concave medially. Parameres each with three distinct long stout hooks and one short hook. Cercus with 13-16 hairs.
Pupa (N = 12). Body length 2.2-2.5 mm.
Head. Integument yellow. Thorax. Integument yellow, moderately covered with round tubercles except posterior half sparsely covered with minute tubercles on each dorsolateral and lateral surface.
Thorax. Gill (Fig. 23J View Figure 23 ) composed of eight slender thread-like filaments, arranged as [3+(1+2)]+2 (or rarely [(2+1)+(1+2)]+2 or [(2+1)+3]+2 or (3+3)+2) from dorsal to ventral, with medium-long common basal stalk; common basal stalk 0.8 times length of interspiracular trunk; stalk of ventral pair of filaments 0.7-1.1 times length of common basal stalk, and 0.5-0.8 times length of interspiracular trunk; primary stalk of dorsal triplet lying against that of lower pair at angle of 70-90° when viewed laterally; in one pupal exuviae with intact gill filaments measured, filaments of dorsal triplets subequal in length (1.8 mm) and thickness, those of middle triplet subequal in length (2.0 mm) and thickness, and two filaments of ventral pair subequal in length (2.3-2.5 mm) and thickness to each other; two filaments of ventral pair 1.6-2.0 times as thick as six other filaments of dorsal and middle triplets when compared basally; all filaments light brown.
Abdomen. Dorsally, all segments light yellow, or unpigmented except segments 1, 2 and 9 light yellow; segments 1 and 2 bare; segment 9 with pair of conical terminal hooks (Fig. 23K View Figure 23 ).
Cocoon. Whitish yellow, slipper-shaped, thinly woven, moderately extended ventrolaterally; anterior margin not thickly woven medially, with no bulge; 2.5-3.0 mm long by 1.5-2.0 mm wide.
Mature larva (N = 6). Body length 3.9-4.2 mm. Body with following color markings: thoracic segments 1-3 ochreous; abdominal segments 1-4 each encircled with light grey band, abdominal segments 5-8 light grey, overlaid with reddish brown pigment on dorsal and dorsolateral surfaces (though often irregularly faded to varying extent dorsomedially) (Fig. 25F View Figure 25 ); abdominal segments 5 and 6 each with pair of small round light grey or reddish brown spots ventrally, and abdominal segment 7 with faint light grey or reddish brown transverse band ventrally.
Head. Head capsule yellow, moderately covered with unpigmented minute setae (though sparsely on lateral and ventral surfaces); head spots faintly positive (rarely negative or indistinct). Antenna: proportional lengths of first, second, and third articles 1.0:0.7-0.8:0.8-0.9. Labral fan with 32-36 primary rays. Hypostoma: anterior row of nine teeth, of which median tooth somewhat longer than each lateral tooth, with four or five hypostomal bristles per side lying nearly parallel to lateral margin. Postgenal cleft (Fig. 23L View Figure 23 ) arrow-head-shaped, medium-long, 2.5 times length of postgenal bridge, usually with apical margin round.
Thorax and Abdomen. Thoracic and abdominal cuticle almost bare except abdominal segments 5-8 moderately covered with unpigmented and slightly-darkened unbranched minute setae on dorsal and dorsolateral surface; last abdominal segment moderately covered with unpigmented minute setae on each side of anal sclerite to base of ventral papillae. Rectal organ compound, each of three lobes with 8-10 finger-like secondary lobules. Anal sclerite with anterior arms 1.1 times as long as posterior ones. Posterior circlet with 72-84 rows of hooklets with up to 13 or 14 hooklets per row.
Etymology.
The species name, namdanense , refers to the name of the locality, Nam Dan, where this species was collected.
Distribution.
Thailand (Chiang Mai and Nan).
Discussion.
This new species is similar to S. lurauense described from Peninsular Malaysia ( Takaoka et al., 2011b) in many characters including the elongate female sensory vesicle and presence of teeth on the outer margin of the female mandible, male hind basitarsus spindle-shaped, and pupal abdominal segment 9 with a pair of small terminal hooks. However, it is barely distinguished from the latter species in the female by the sensory vesicle 0.64-0.68 times the length of the third maxillary palpal segment (0.50-0.54 times in S. lurauense ) and in the male by the upper-eye facets in 15 or 16 vertical columns and 16 or 17 horizontal rows (14 or 15 vertical columns and 14 or 15 horizontal rows in S. lurauense ) and the sensory vesicle 0.33 times the length of the third maxillary palpomere (0.25-0.29 times in S. lurauense ), and in the pupa by the stalk of the ventral pair of filaments 0.5-0.8 times as long as the interspiracular trunk (0.9-1.0 times in. S. lurauense ).
This new species is almost indistinguishable from S. thituyenae from Vietnam ( Takaoka et al. 2015), though there appears to be a slight difference in the number of the outer teeth of the female mandible, which is three to five in this new species and eight in S. thituyenae . Further comparison is needed when the male and mature larva of S. thituyenae become available.
This new species is distinguished from S. klonglanense sp. nov. by the female wing length (2.0 mm in this new species versus 1.6 mm in S. klonglanense sp. nov.), and number of male upper-eye facets in 15 or 16 vertical columns and 16 or 17 horizontal rows (13 or 14 vertical columns and 14 or 15 horizontal rows in S. klonglanense sp. nov.).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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