Simulium (Gomphostilbia) junkumae Takaoka, Srisuka & Saeung, 2020

Takaoka, Hiroyuki, Srisuka, Wichai, Fukuda, Masako & Saeung, Atiporn, 2020, Twenty-one new species of the Simulium (Gomphostilbia) asakoae species group (Diptera, Simuliidae) in Thailand, with their genetic relationships, ZooKeys 950, pp. 51-152 : 51

publication ID

https://dx.doi.org/10.3897/zookeys.950.51298

publication LSID

lsid:zoobank.org:pub:3E805885-D335-4FB3-AE8D-FA443FAD82AE

persistent identifier

https://treatment.plazi.org/id/327F3EB9-C555-4B08-A691-789310BB612F

taxon LSID

lsid:zoobank.org:act:327F3EB9-C555-4B08-A691-789310BB612F

treatment provided by

ZooKeys by Pensoft

scientific name

Simulium (Gomphostilbia) junkumae Takaoka, Srisuka & Saeung
status

sp. nov.

Simulium (Gomphostilbia) junkumae Takaoka, Srisuka & Saeung sp. nov. Figs 18 View Figure 18 , 25K View Figure 25

Material examined.

Holotype: Male (with its associated pupal exuviae and cocoon) (in 80% ethanol) labeled as "Holotype: Simulium junkumae male, QSBG col. no. 92, Thailand, 7-IV-2017, by W. Srisuka", collected from a small stream (width 40 cm, depth 3 cm, bed sandy, moderate flow, pH 6.2, 19 °C, partially shaded, elevation 1,395 m, 18°49'09.5"N, 98°53'14.3"E), at Doi Pui Temple, Doi Suthep Pui, Muang District, Chiang Mai Province, Thailand, 7-IV-2017, by W. Srisuka (Coll. No. 92).

Paratypes: Five females, five males (thorax of one male for DNA analysis) (with their associated pupal exuviae and cocoons), and six mature larvae (two mature larvae for DNA analysis) (in 80% ethanol), same data as for holotype.

Diagnosis.

Female: relatively narrower frons against the head width (1.0:4.7-5.5), and mandible without teeth on the outer margin (Fig. 18A View Figure 18 ). Male: greater number of upper-eye facets in 15-17 vertical columns and 15-17 horizontal rows on each side. Larva: small number of the primary rays of the labral fan (24 or 25), postgenal cleft as long as or little shorter than the postgenal bridge (Fig. 18M View Figure 18 ) and abdominal segments 1-3 entirely grey (Fig. 25K View Figure 25 ).

Description.

Female (N = 5). Body length 2.0-2.3 mm.

Head. Frontal ratio 1.8-1.9:1.0:2.5-3.2; frons:head ratio 1.0:4.7-5.5. Labrum 0.64-0.67 times length of clypeus. Maxillary palpus: proportional lengths of third, fourth, and fifth palpal segments 1.0:1.0-1.1:2.0-2.1; sensory vesicle medium sized, ellipsoidal (0.27-0.32 times length of third palpal segment), with medium opening. Lacinia with ten or eleven inner and 14 or 15 outer teeth. Mandible (Fig. 18A View Figure 18 ) with 22-26 inner teeth and lacking distinct outer teeth (though outer margin undulated from tip for some short distance appearing to have ca. ten vestigial teeth).

Legs. Foreleg: trochanter dark yellow to light brown; femur light brown with apical cap medium brown (though extreme tip yellowish); basitarsus moderately dilated, 6.7-7.0 times as long as its greatest width. Midleg: trochanter dark yellow except basal half yellow; tarsus dark brown to brownish black except basal one-fourth of basitarsus dark yellow (its border not well defined). Hind leg: tibia yellowish white on little more than basal half and light brown to brownish black on rest; basitarsus (Fig. 18B View Figure 18 ) 5.9 times as long as wide, and 0.7 and 0.6 times as wide as greatest widths of tibia and femur, respectively; calcipala (Fig. 18B View Figure 18 ) nearly as long as width at base, and 0.56 times as wide as greatest width of basitarsus.

Wing. Length 2.1-2.3 mm.

Abdomen. Dorsal surface of abdomen medium to dark brown except anterior four-fifths of segment 2 whitish. Ventral surface of segment 2 whitish and those of other segments light to dark brown; sternal plate on segment 7 undeveloped.

Terminalia. Sternite 8 bare medially, with 25-28 medium-long to long hairs together with two or six slender short hairs on each side. Ovipositor valve triangular, thin, membranous, moderately covered with microsetae interspersed with two to four short hairs; inner margins nearly straight or slightly sinuous, somewhat sclerotized, and moderately separated from each other. Paraproct in ventral view with five or six sensilla on anteromedial surface; paraproct in lateral view somewhat produced ventrally beyond ventral tip of cercus, 0.6 times as long as wide, with 25-28 medium-long to long hairs on ventral and lateral surfaces. Cercus in lateral view 0.4-0.5 times as long as wide. Spermatheca ellipsoidal, 1.3 times as long as its greatest width.

Male (N = 6). Body length 2.2-2.3 mm.

Head. Slightly wider than thorax. Upper eye dark brown, consisting of large facets in 15-17 vertical columns and 15-17 horizontal rows on each side. Antenna: first flagellomere elongate, 1.6-1.8 times length of second. Maxillary palpus: proportional lengths of third, fourth, and fifth palpal segments 1.0:1.0:2.4-2.6; sensory vesicle ellipsoidal, 0.17-0.23 times length of third palpal segment.

Legs. Foreleg: tibia light grey to light brown except basal tip and outer surface of basal two-thirds whitish, and apical one-third dark brown; basitarsus moderately dilated, 7.8-8.1 times as long as its greatest width. Midleg: basitarsus dark brown except basal tip yellow. Hind leg: coxa medium brown; tibia dark brown to brownish black except little more than basal one-third whitish yellow; tarsus (Fig. 18C View Figure 18 ) brownish black except little less than basal half of basitarsus and basal one-third of second tarsomere yellow; basitarsus (Fig. 18C View Figure 18 ) 3.7-4.0 times as long as wide, and 0.9 and 1.0 times as wide as greatest width of tibia and femur, respectively; calcipala (Fig. 18C View Figure 18 ) slightly shorter than basal width, and 0.33 times as wide as greatest width of basitarsus.

Wing. Length 2.2-2.4 mm. Subcosta with 7-12 hairs.

Genitalia. Coxite in ventral view (Fig. 18D View Figure 18 ) nearly rectangular, 1.7 times as long as its greatest width. Style in ventral view (Fig. 18D View Figure 18 ) with triangular apex; style in ventrolateral view (Fig. 18E, F View Figure 18 ) slightly tapered toward apex or nearly parallel-sided from basal one-third to apex, and 0.8 times length of coxite. Ventral plate in ventral view (Fig. 18D View Figure 18 ) with body transverse, 0.46 times as long as wide, with anterior margin produced anteromedially, posterior margin nearly straight or somewhat concave medially, and lateral margin emarginated medially; basal arms of moderate length, nearly parallel-sided, then convergent apically; ventral plate in caudal view (Fig. 18I View Figure 18 ) trapezoidal, with ventral margin nearly straight or slightly concave ventrally. Cercus with 14 or 15 hairs.

Pupa (N = 11). Body length 2.4-2.8. mm.

Thorax. Integument moderately covered with round tubercles except dorsal and dorsolateral surfaces of posterior half sparsely covered with tubercles. Gill (Fig. 18J View Figure 18 ) composed of eight slender thread-like filaments, arranged as [3+(1+2)]+2 or [3+(2+1)]+2 from dorsal to ventral; common basal stalk 0.7-0.8 times length of interspiracular trunk; stalk of ventral pair of filaments 0.7-1.2 times length of common basal stalk, and 0.5-0.9 times length of interspiracular trunk; primary stalk of dorsal triplet lying against that of lower pair at angle of 60° when viewed laterally; filaments of dorsal and middle triplets subequal in length (2.0-2.6 mm) and thickness to one another; two filaments of ventral pair subequal in length (3.0-3.9 mm) and thickness to each other and 1.6-1.8 times as thick as six other filaments of dorsal and middle triplets when compared basally.

Abdomen. Dorsally, all segments light yellow; segments 1 and 2 without tubercles; segment 9 with pair of wide flat terminal hooks (Fig. 18K View Figure 18 ), of which outer margin is 2.2-2.6 times length of inner margin and crenulated when viewed caudally.

Cocoon (Fig. 18L View Figure 18 ). Wall-pocket-shaped, moderately woven, moderately extended ventrolaterally; anterior margin moderately woven medially, rarely with bulge; individual threads visible; 3.3-3.9 mm long by 2.0-2.5 mm wide.

Mature larva (N = 4). Body length 4.9-5.4 mm. Body creamy white with following color markings: thoracic segment 1 encircled with distinct reddish brown band (though disconnected ventromedially), thoracic segments 2 and 3 ochreous on ventral surface; abdominal segments 1-3 entirely grey, abdominal segment 4 with reddish brown transverse band dorsally (though often partially to completely faded, leaving narrow band or small spot(s) dorsally), abdominal segments 5 and 6 each with distinct reddish brown, W-shaped, transverse band (of which central and dorsolateral parts marked) along posterior margin on dorsal and dorsolateral surfaces (though band on abdominal segment 6 often partially faded, leaving one round dorsomedial spot and two larger dorsolateral lateral spots); abdominal segments 7 and 8 covered with reddish brown pigments on dorsal and dorsolateral surfaces (though central portion often faded to varying extent) (Fig. 25K View Figure 25 ).

Head. Head capsule yellow except eye-spot region whitish, sparsely covered with minute setae (though moderately on dorsal surface); head spots faintly to moderately positive or indistinct. Antenna: proportional lengths of first, second, and third articles 1.0:0.7-0.8:0.7-0.8. Labral fan with 24 or 25 primary rays. Postgenal cleft (Fig. 18M View Figure 18 ) rounded or quadrate, 0.9-1.0 times length of postgenal bridge.

Abdomen. Rectal organ compound, each of three lobes with 8-11 finger-like secondary lobules. Anal sclerite: anterior arms 1.0-1.2 times as long as posterior ones. Posterior circlet with 81-84 rows of hooklets with up to 14 hooklets per row.

Etymology.

The species name junkumae is in honor of Assistant Prof. Dr. Anuluck Junkum, Department of Parasitology, Faculty of Medicine, Chiang Mai University, Thailand, for her kind help in the field and laboratory works of black flies.

Distribution.

Thailand (Chiang Mai).

Discussion.

This new species is similar to S. hongthaii Takaoka, Sofian-Azirun & Ya’cob described from Vietnam ( Takaoka et al. 2014a) in having a greater number of male upper-eye facets. However, it is distinguished from the latter species in the female by the narrower frons (frons:head ratio 1:4.7-5.5 in the new species versus 1:4.1-4.2 in S. hongthaii ), in the male by the subcosta with hairs (subcosta bare in S. hongthaii ) and in the larva by abdominal segments 1-3 grey (Fig. 25K View Figure 25 ) (abdominal segments 1-4 greyish in S. hongthaii ).

The larva of S. sp. nr. asakoae -2 reported from Thailand by Jitklang et al. (2008) has a medium-sized postgenal cleft and abdominal segments 1-3 each with a greenish transverse band, both characters resembling those of this new species, but it differs by lacking distinct color markings on abdominal segments 5-8.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Simuliidae

Genus

Simulium