Simulium (Gomphostilbia) sutheppuiense 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/10B68AD2-5E0C-4E3C-9E9F-040769084BE6

taxon LSID

lsid:zoobank.org:act:10B68AD2-5E0C-4E3C-9E9F-040769084BE6

treatment provided by

ZooKeys by Pensoft

scientific name

Simulium (Gomphostilbia) sutheppuiense Takaoka, Srisuka & Saeung
status

sp. nov.

Simulium (Gomphostilbia) sutheppuiense Takaoka, Srisuka & Saeung sp. nov. Figs 5 View Figure 5 , 25C View Figure 25

Material examined.

Holotype: Male (with its associated pupal exuviae and cocoon) (in 80% ethanol) labeled as "Holotype: Simulium sutheppuiense male, QSBG col. no. 92, Thailand, 7-IX-2017, by W. Srisuka", collected from a small stream (width 60 cm, depth 15 cm, bed sandy, moderate flow, pH 6.9, 20 °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-IX-2017, by W. Srisuka (Coll. No. 92).

Paratypes: One female (thorax for DNA analysis), three males (thorax of one male for DNA analysis) (with their associated pupal exuviae and cocoons), and five mature larvae (one mature larva for DNA analysis) (in 80% ethanol), same data as for holotype;

Diagnosis.

Female: mandible with three teeth on the outer margin (Fig. 5A View Figure 5 ). Male: small number of upper-eye facets in eleven vertical columns and 13 horizontal rows. Pupa: dorsal triplet of the gill filaments with an extremely short stalk (Fig. 5G View Figure 5 ). Larva: postgenal cleft 1.2-2.4 as long as the postgenal bridge (Fig. 5J View Figure 5 ) and abdominal segments 1-4 light ochreous (Fig. 25C View Figure 25 ).

Description.

Female (N = 1). Body length 2.0 mm.

Head. Frontal ratio 2.0:1.0:2.5; frons:head ratio 1.0:4.6. Labrum 0.57 times length of clypeus. Maxillary palpus: proportional lengths of third, fourth, and fifth palpal segments 1.0:1.2:2.7; sensory vesicle 0.29-0.32 times length of third palpal segment. Lacinia with ten or eleven inner and 13 or 14 outer teeth. Mandible (Fig. 5A View Figure 5 ) with 23 inner teeth and three outer teeth at some distance from tip.

Legs. Foreleg: basitarsus moderately dilated, 6.3 times as long as its greatest width. Midleg: tarsus dark brown to brownish black though basal half of basitarsus yellow (its border not well defined). Hind leg: coxa light brown; tibia yellowish white on basal three-fifths and light brown to brownish black on rest; basitarsus 5.3 times as long as wide, and 0.8 and 0.6 times as wide as greatest widths of tibia and femur, respectively.

Wing. Length 2.0 mm.

Abdomen. Dorsal surface of abdomen medium to dark brown except most of segment 2 ochreous.

Terminalia. Sternite 8 with 25 or 26 medium-long to long hairs together with three or four slender short hairs on each side. Ovipositor valves each moderately covered with microsetae interspersed with two or three short hairs. Paraproct in ventral view with three or four sensilla on anteromedial surface; paraproct in lateral view 0.5 times as long as wide, and with 24 medium-long to long hairs on ventral and lateral surfaces. Cercus in lateral view 0.5 times as long as wide. Spermatheca 1.5 times as long as its greatest width.

Male (N = 4). Body length 2.0-2.2 mm.

Head. Slightly wider than thorax. Upper eye dark brown, consisting of large facets in eleven vertical columns and 13 horizontal rows. Antenna light to medium brown except scape, pedicel, and base of first flagellomere yellow; first flagellomere elongate, 1.8-1.9 times length of second one. Maxillary palpus: proportional lengths of third, fourth, and fifth palpal segments 1.0:1.1:2.6; sensory vesicle 0.15 times length of third palpal segment.

Legs. Foreleg: tibia whitish yellow except apical three-tenths dark brown; basitarsus slightly dilated, 7.5-7.9 times as long as its greatest width. Hind leg: coxa medium brown; tibia dark brown to brownish black except little less than basal half whitish yellow; tarsus (Fig. 5B View Figure 5 ) brownish black except basal two-fifths of basitarsus and basal one-third of second tarsomere whitish yellow; basitarsus (Fig. 5B View Figure 5 ) enlarged, 3.6-3.8 times as long as wide, and 1.0 and 1.1 times as wide as greatest width of tibia and femur, respectively; calcipala (Fig. 5B View Figure 5 ) 0.3 times as wide as greatest width of basitarsus.

Wing. Length 1.9-2.0 mm. Subcosta with 1-11 hairs (though no hairs in one male).

Genitalia. Coxite in ventral view (Fig. 5C View Figure 5 ) nearly rectangular, 1.8 times as long as its greatest width. Style in ventral view (Fig. 5C View Figure 5 ) with round or truncate apex; style in ventrolateral view (Fig. 5D View Figure 5 ) slightly tapered toward apex, with truncated apex, and 0.8 times as long as coxite. Ventral plate in caudal view (Fig. 5F View Figure 5 ) with ventral margin nearly straight. Cercus with 17 or 18 hairs.

Pupa (N = 5). Body length 2.5-2.7 mm.

Head. Integument yellow.

Thorax. Integument yellow, moderately covered with round tubercles except dorsolateral surface of posterior half sparsely covered with tubercles. Gill (Fig. 5G View Figure 5 ) composed of eight slender thread-like filaments, arranged as (3+3)+2 or [3+(1+2)]+2 from dorsal to ventral; common basal stalk 0.6-0.7 times length of interspiracular trunk; dorsal and middle triplets sharing short stalk, and each composed of three individual filaments arising at same level except middle triplet rarely composed of one individual and two paired filaments with extremely short secondary stalk; stalk of ventral pair of filaments 1.0-1.3 times length of common basal stalk, and 0.6-0.8 times length of interspiracular trunk; primary stalk of dorsal triplet lying against that of lower pair at angle of 40-70° when viewed laterally; filaments of dorsal and middle triplets subequal in length (1.5-1.8 mm) and thickness to one another; two filaments of ventral pair subequal in length (2.3-2.5 mm) and thickness to each other and 1.3-1.5 times as thick as six other filaments of dorsal and middle triplets when compared basally.

Abdomen. Dorsally, all segments unpigmented except segments 1, 2, and 9 light yellowish; segments 1 and 2 without minute tubercles; segment 9 with pair of wide flat terminal hooks (Fig. 5H View Figure 5 ), of which outer margin 2.8-2.9 times length of inner margin and crenulated when viewed caudally.

Cocoon (Fig. 5I View Figure 5 ). Light yellow to light brown, slipper-shaped, moderately woven, widely extended ventrolaterally; anterior margin not thickly woven medially, without bulge or short projection; individual threads visible; 3.2-3.6 mm long by 1.9-2.5 mm wide.

Mature larva (N = 4). Body length 4.7-5.5 mm. Body light ochreous with following color markings: thoracic segment 1 encircled with light to dark brown band (though disconnected ventrally), thoracic segments 2 and 3 ochreous on ventral surface; abdominal segment 4 faintly with reddish brown transverse band (though often entirely faded), abdominal segments 5 and 6 each with distinct reddish brown, W-shaped, transverse band dorsally along posterior margin, though often partially faded leaving one round dorsomedial spot and two lateral spots of various size and shape, dorsal and dorsolateral surface of abdominal segments 5-8 faintly to moderately covered with pinkish or reddish brown pigment (Fig. 25C View Figure 25 ).

Head. Head capsule yellow except eye-spot region whitish; head spots moderately positive or indistinct. Antenna: proportional lengths of first, second, and third articles 1.0:0.7-0.8:0.8. Labral fan with 29 or 30 primary rays. Postgenal cleft (Fig. 5J View Figure 5 ) small to medium sized, rounded or arrow-headed, 1.2-2.4 times length of postgenal bridge.

Thorax and Abdomen. Thoracic and abdominal cuticle sparsely covered with unpigmented minute setae, though few posterior abdominal segments sparsely covered with dark minute unbranched setae dorsally. Rectal organ compound, each of three lobes with nine or ten finger-like secondary lobules. Posterior circlet with 86-89 rows of hooklets with up to 14 or 15 hooklets per row.

Etymology.

The species name, sutheppuiense , refers to the locality name, Doi Suthep Pui, where this species was collected.

Distribution.

Thailand (Chiang Mai).

Discussion.

This new species is similar to S. asakoae in many characters including the presence of teeth on the outer margin of the female mandible, and small number of male upper-eye facets. However, it is distinguished from the latter species in the female by the shorter sensory vesicle relative to the third palpal segment, in the male by the dark brown upper-eye (large) facets, in the pupa by the light yellow dorsum of abdominal segments 1-3, and in the larva by abdominal segments 1-4 light ochreous (Fig. 25C View Figure 25 ).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Simuliidae

Genus

Simulium