Simulium (Gomphostilbia) klonglanense 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/1D6E82E6-C730-4C82-9809-6F526A9851FB

taxon LSID

lsid:zoobank.org:act:1D6E82E6-C730-4C82-9809-6F526A9851FB

treatment provided by

ZooKeys by Pensoft

scientific name

Simulium (Gomphostilbia) klonglanense Takaoka, Srisuka & Saeung
status

sp. nov.

Simulium (Gomphostilbia) klonglanense Takaoka, Srisuka & Saeung sp. nov. Figs 22 View Figure 22 , 25E View Figure 25

Material examined.

Holotype: Male (with its associated pupal exuviae and cocoon) (in 80% ethanol) labeled as "Holotype: Simulium klonglanense male, QSBG col. no. 144, Thailand, 27-VI-2013, by W. Srisuka", collected from a stream of Klong Nam Lai (width 1.4 m, depth 13 cm, bed sandy, moderate flow, pH 6.2, 25.8 °C, exposed to the sun, elevation 196 m, 16°12'28.3"N, 99°15'47.8"E), at Klong Lan District, Kham Phaeng Phet Province, Thailand, 27-VI-2013, by W. Srisuka (Coll. No. 144).

Paratypes: Three females, one male (thorax for DNA analysis) (with their associated pupal exuviae and cocoons), and eight mature larvae (in 80% ethanol), same data as for holotype.

Diagnosis.

Female: sensory vesicle elongated (Fig. 22A View Figure 22 ) and mandible with four distinct teeth on the outer margin (Fig. 22B View Figure 22 ). Male: upper-eye (large) facets in 13 or 14 vertical columns and 14 or 15 horizontal rows on each side, and moderately widened hind basitarsus 0.9 times as wide as the hind tibia and femur. Pupa: small terminal hooks (Fig. 22K View Figure 22 ). Larva: postgenal cleft 3.7-4.0 times as long as the postgenal bridge (Fig. 22M View Figure 22 ) and abdominal segments 1-4 grey (Fig. 25E View Figure 25 ).

Description.

Female (N = 3). Body length 1.8 mm.

Head. Frontal ratio 1.8:1.0:2.2; frons:head ratio 1.0:4.2. Labrum 0.59 times length of clypeus. Maxillary palpus: proportional lengths of third, fourth, and fifth palpal segments 1.0:1.0:2.1; sensory vesicle (Fig. 22A View Figure 22 ) elongated (0.65-0.68 times length of third palpal segment). Lacinia with 10 inner and 14-16 outer teeth. Mandible (Fig. 22B View Figure 22 ) with 27 inner teeth and four outer teeth at some distance from tip.

Legs. Foreleg: basitarsus moderately dilated, 5.2-5.4 times as long as its greatest width. Midleg: tarsus light to medium brown though little less than basal half of basitarsus yellow (its border not well defined). Hind leg: coxa light brown; tibia yellowish white on basal two-thirds and light to dark brown on rest; tarsus medium brown except basal two-thirds (though base light brown) and basal half of second tarsomere yellowish white; basitarsus 5.8-6.6 times as long as wide, and 0.7 and 0.6 times as wide as greatest widths of tibia and femur, respectively.

Wing. Length 1.6 mm.

Abdomen. Dorsal surface of abdomen medium to dark brown except most of segment 2 ochreous (though narrow portion along posterior margin somewhat darkened).

Terminalia. Sternite 8 with 17 medium-long to long hairs together with four slender short hairs on each side. Genital fork (Fig. 22C View Figure 22 ) of usual inverted-Y form, with slender stem; inner margins of arms divergent from each other. Paraproct in ventral view with 3-5 sensilla on anteromedial surface; paraproct in lateral view 0.6 times as long as wide, with 16 medium-long to long hairs on ventral and lateral surfaces. Cercus in lateral view short, rounded posteriorly, 0.5 times as long as wide. Spermatheca 1.44 times as long as its greatest width; both accessory ducts slender, subequal in diameter to each other and slightly wider than major one.

Male (N = 2). Body length 2.0 mm.

Head. Somewhat wider than thorax. Upper eye medium brown, consisting of large facets in 13 or 14 vertical columns and 14 or 15 horizontal rows on each side. Antenna: first flagellomere elongate, 1.7 times length of second. Maxillary palpus: proportional lengths of third, fourth, and fifth palpal segments 1.0:1.2:2.7; sensory vesicle (Fig. 22D View Figure 22 ) small, ellipsoidal (0.25-0.27 times length of third palpal segment).

Thorax. Scutum medium to dark brown except anterolateral calli ochreous, with three dark-brown longitudinal vittae (one medial and two submedial), white pruinose except three longitudinal vittae non-pruinose when illuminated anterodorsally and viewed dorsally. Scutellum medium brown. Postnotum medium to dark brown.

Legs. Foreleg: basitarsus slightly dilated, 6.8 times as long as its greatest width. Hind leg: coxa light brown; tibia dark brown except little less than basal half whitish yellow; tarsus (Fig. 22E View Figure 22 ) medium brown except little less than basal half of basitarsus and little less than basal half of second tarsomere whitish yellow; basitarsus (Fig. 22E View Figure 22 ) enlarged, 4.2 times as long as wide, and 0.9 and 0.9 times as wide as greatest width of tibia and femur, respectively; calcipala (Fig. 22E View Figure 22 ) slightly shorter than basal width, and 0.21 times as wide as greatest width of basitarsus.

Wing. Length 1.5 mm. Subcosta with 0-2 hairs.

Genitalia. Style in ventral view (Fig. 22F View Figure 22 ) bent inward, with round apex having single spine; style in ventrolateral view (Fig. 22G View Figure 22 ) slightly tapered toward apex, with round apex. Ventral plate in ventral view (Fig. 22F View Figure 22 ): basal arms of moderate length, nearly parallel-sided, then slightly convergent apically; ventral plate in caudal view (Fig. 22I View Figure 22 ) trapezoidal, with ventral margin nearly straight. Cercus with 12 or 13 hairs.

Pupa (N = 5). Body length 2.0-2.4 mm.

Head. Integument light yellow.

Thorax. Integument light yellow, moderately covered with round tubercles except dorsolateral surface of posterior one-third nearly bare. Gill (Fig. 22J View Figure 22 ) composed of eight slender thread-like filaments, arranged as [3+(1+2)]+2 or [(2+1)+(1+2)]+2 or [(2+1)+3]+2) from dorsal to ventral; common basal stalk 0.7-0.8 times length of interspiracular trunk; stalk of ventral pair of filaments variable in length, 0.6-1.2 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 80-90° when viewed laterally; filaments of dorsal triplet subequal in length (1.8 mm) and thickness to one another; filaments of dorsal triplet subequal in length (1.9-2.1 mm) and thickness to one another; two filaments of ventral pair subequal in length (tips of filaments of ventral pair lost, thus not possible to measure their lengths, which are probably little more than 2.4 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; all filaments pale yellow.

Abdomen. Dorsally, all segments unpigmented except segment 9 light yellow; segments 1 and 2 without minute tubercles; segment 9 with pair of small flat terminal hooks (Fig. 22K View Figure 22 ) when viewed caudally.

Cocoon (Fig. 22L View Figure 22 ). Whitish yellow to medium brown, slipper-shaped, moderately woven, moderately extended ventrolaterally; anterior margin moderately woven medially, with or without bulge; individual threads visible or not visible; 2.4-3.0 mm long by 1.7-2.1 mm wide.

Mature larva (N = 8). Body length 3.3-4.0 mm. Body with following color markings: thoracic segment 1 encircled with grey (or greyish ochreous) band (though disconnected ventromedially), thoracic segments 2 and 3 grey or ochreous on ventral surface; abdominal segments 1-4 each encircled with greyish band, abdominal segments 5-8 greyish on dorsal and dorsolateral surfaces; abdominal segment 4 with or without reddish purplish transverse band (though often partially faded medially and ventrally), abdominal segments 5-8 each faintly to moderately overlaid with reddish purplish pigments dorsally and dorsolaterally (though faded medially to various extent), abdominal segments 5 and 6 each with pair of small grey or reddish purplish spots ventrally, and abdominal segment 7 with grey transverse band (overlaid with reddish purplish pigment) ventrally (Fig. 25E View Figure 25 ).

Head. Head capsule yellow except eye-spot region whitish; head spots indistinct. Antenna: proportional lengths of first, second, and third articles 1.0:0.8:0.8-1.0. Labral fan with 30-34 primary rays. Postgenal cleft (Fig. 22M View Figure 22 ) long, arrowhead shaped, 3.7-4.0 times length of postgenal bridge.

Abdomen. Rectal organ compound, each of three lobes with six to eight finger-like secondary lobules. Anal sclerite of usual X-form, with anterior arms nearly as long as posterior ones. Posterior circlet with 71-74 rows of hooklets with up to 14 hooklets per row.

Etymology.

The species name, klonglanense , refers to the district, Klong Lan, where this species was collected.

Distribution.

Thailand (Kham Phaeng Phet).

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, presence of teeth on the outer margin of the female mandible, and similar number of male upper-eye facets. However, it is distinguished from the latter species by the relative length of the female sensory vesicle against the third palpal segment (0.65-0.68 in this new species versus 0.50-0.54 in S. lurauense ), and male hind basitarsus (0.9 times as wide as the hind tibia and femur in this new species versus 0.8 times as wide as the hind tibia and 0.7-0.8 times as wide as the hind femur in S. lurauense ).

This new species is similar to S. quychauense Takaoka & Chen from Vietnam, which is known only for the male and pupa ( Takaoka et al. 2017a) in having a similar number of male upper-eye (large) facets and small pupal terminal hooks. However, it is barely distinguished from the latter species by the ventral margin of the ventral plate nearly straight when viewed posteriorly (somewhat convex ventrally in S. quychauense ) and pupal abdominal segment 9 with spine-combs (without spine-combs in S. quychauense ).

This new species is similar to S. thituyenae Takaoka & Pham from Vietnam, which is known only for the female and pupa ( Takaoka et al. 2015), but is barely distinguished from the latter species by the wing length (1.6 mm in this new species versus 2.0 mm in S. thituyenae ), number of the outer teeth of the female mandible (four in this new species versus eight in S. thituyenae ), and the angle of the stalk of the dorsal triplet of the pupal gill against that of the ventral pair of filaments (80-90° in this new species versus 60° in S. thituyenae ).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Simuliidae

Genus

Simulium

SubGenus

Gomphostilbia