Simulium (Gomphostilbia) teerachanense Takaoka, Srisuka & Fukuda, 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/40239302-BA1E-4A02-A968-0C4AA624FF15

taxon LSID

lsid:zoobank.org:act:40239302-BA1E-4A02-A968-0C4AA624FF15

treatment provided by

ZooKeys by Pensoft

scientific name

Simulium (Gomphostilbia) teerachanense Takaoka, Srisuka & Fukuda
status

sp. nov.

Simulium (Gomphostilbia) teerachanense Takaoka, Srisuka & Fukuda sp. nov. Figs 6 View Figure 6 , 25A View Figure 25

Material examined.

Holotype: Male (with its associated pupal exuviae and cocoon) (in 80% ethanol) labeled as "Holotype: Simulium teerachanense male, QSBG col. no. 105, Thailand, 14-VII-2017, by W. Srisuka", collected from a small stream (width 25 cm, depth 2.5 cm, bed sandy, moderate flow, pH 6.8, 21.9 °C, partially shaded, elevation 974 m, 18°20'35.8"N, 98°01'23.8"E), at Tee Ra Chan Waterfall, Mae La-noi, Mae Hong Son Province, Thailand, 14-VII-2017, by W. Srisuka (Coll. No. 105).

Paratypes: Eight males (thoraces of two males for DNA analysis) (with their associated pupal exuviae and cocoons) and four mature larvae (in 80% ethanol), same data as for holotype. One mature larva (for DNA analysis) collected from a stream (elevation 817m, 19°11'22.0"N, 98°04'12.1"E), Huai Hee Village, Mae Sarieng, Mae Hong Song Province, northern Thailand, 13-VII-2017, by W. Srisuka (Coll. No. 106).

Diagnosis.

Male: small number of upper-eye facets in eleven vertical columns and 13 horizontal rows and antenna almost entirely yellow. Larva: postgenal cleft long, 2.8-3.3 times as long as the postgenal bridge (Fig. 6I View Figure 6 ) and abdominal segments 1-4 dull ochreous (Fig. 25A View Figure 25 ).

Description.

Male (N = 9). Body length 2.0-2.2 mm.

Head. Somewhat wider than thorax. Upper eye dark brown, consisting of large facets in eleven vertical columns and 13 horizontal rows. Antenna entirely yellow, though few apical flagellomeres slightly darkened in some males; first flagellomere elongate, 1.8 times length of second. Maxillary palpus: proportional lengths of third, fourth, and fifth palpal segments 1.0:1.2:2.5; sensory vesicle small, globular or ellipsoidal (0.16-0.17 times length of third palpal segment).

Legs. Foreleg: tibia whitish yellow except apical three-tenths dark brown; basitarsus slightly dilated, 7.3-7.5 times as long as its greatest width. Hind leg: coxa light brown; tibia dark brown to brownish black except little more than basal two-fifths whitish yellow; tarsus (Fig. 6A View Figure 6 ) brownish black except little less than basal half of basitarsus and basal one-third of second tarsomere whitish yellow; basitarsus (Fig. 6A View Figure 6 ) enlarged, wedge-shaped, 3.6-3.8 times as long as wide, and 0.9-1.0 and 1.0 times as wide as greatest width of tibia and femur, respectively; calcipala (Fig. 6A View Figure 6 ) slightly shorter than basal width, and 0.35 times as wide as greatest width of basitarsus.

Wing. Length 1.9-2.0 mm. Subcosta with one to four hairs, though no hairs in three males.

Abdomen. Dorsal surface of abdomen medium brown to brownish black, except most of segment 2 yellow to light ochreous.

Genitalia. Ventral plate in ventral view (Fig. 6B View Figure 6 ) with basal arms nearly parallel-sided, then convergent apically; ventral plate in caudal view (Fig. 6E View Figure 6 ) with ventral margin nearly straight. Cercus with 12 or 13 hairs.

Pupa (N = 9). Body length 2.4-2.6 mm.

Head. Integument yellow.

Thorax. Integument yellow, moderately covered with round tubercles, except dorsolateral surface of posterior half sparsely covered with tubercles. Gill (Fig. 6F View Figure 6 ) composed of eight slender thread-like filaments, arranged as [3+(1+2)]+2 or (3+3)+2 from dorsal to ventral; common basal stalk 0.6-0.7 times length of interspiracular trunk; stalk of ventral pair of filaments variable in length, 0.8-1.3 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; filaments of dorsal and middle triplet subequal in length (1.5-2.1 mm) and thickness to one another; two filaments of ventral pair subequal in length (2.5-3.0 mm) and thickness to each other and 1.4-1.7 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 and bases of spine-combs of segments 6-8 light yellow; segments 1 and 2 without minute tubercles; segment 9 with pair of wide flat terminal hooks (Fig. 6G View Figure 6 ), of which outer margin 2.6-2.9 times length of inner margin and crenulated when viewed caudally.

Cocoon (Fig. 6H View Figure 6 ). Yellow to dark brown, slipper-shaped, moderately woven, extended ventrolaterally; anterior margin thickly woven medially, without bulge or short projection; individual threads visible; 2.9-3.3 mm long by 2.0-2.1 mm wide.

Mature larva (N = 4). Body length 4.5-5.5 mm. Body dull ochreous with following color markings: thoracic segment 1 encircled with dark brown band (though disconnected ventrally), abdominal segments 5 and 6 each with distinct reddish brown, W-shaped, transverse band dorsally along posterior margin, though that on segment 6 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 covered with pinkish or reddish brown pigments (Fig. 25A View Figure 25 ).

Head. Head capsule yellow except eye-spot region whitish; head spots indistinct except those on lateral and ventral surfaces faintly positive. Antenna: proportional lengths of first, second, and third articles 1.0:0.7-0.8:0.8-1.0. Labral fan with 28-30 primary rays. Postgenal cleft (Fig. 6I View Figure 6 ) long, rounded or arrow-headed, 2.8-3.3 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 7-11 finger-like secondary lobules. Posterior circlet with 90-95 rows of hooklets with up to 14 hooklets per row.

Female. Unknown.

Etymology.

The species name, teerachanense , refers to the name of the waterfall, Tee Ra Chan, where this species was collected.

Distribution.

Thailand (Mae Hong Son).

Discussion.

This new species is similar to S. roslihashimi described from Peninsular Malaysia ( Takaoka et al. 2011b) in many characters including the small number of the male upper-eye large facets and male antenna almost entirely yellow. However, it is distinguished from the latter species by the male fore basitarsus 7.3-7.5 times as long as its greatest width (6.6-6.8 times in S. roslihashimi ) and ventral plate with its ventral margin nearly straight (Fig. 6E View Figure 6 ) when viewed posteriorly (ventral plate rounded ventrally in S. roslihashimi ).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Simuliidae

Genus

Simulium