Kribiodosis mulu, Tang & Cranston & Peter S., 2025

Kribiodosis mulu , new species

( Figs. 1B, D, G View Fig ; 2D–F, J–L View Fig )

Material examined. Holotype male, slide mounted in Euparal, MALAYSIA: Sarawak, Gunung Mulu National Park, Melinau Paku tributary stream, 75 m a.s.l., 04°1″48.8″N

114°49′4.4″E, 12 June 2023, light trap, coll. H.Q. Tang ( EJNU) . Paratypes 2 males, one on slide under 7 coverslips; hypopygium, wing and legs of partial additional DNA voucher specimen under 8 th coverslip; as holotype ( ANIC) ; 2 males, as holotype, except 10 July 2024 ( SFC) .

Etymology. From the type locality, Gunung Mulu National Park. To be treated as a noun in apposition.

Description. Adult males (n = 2–3). Colour ( Fig. 1B View Fig ) generally brown, thorax with darker brown vittae, scutellum yellow. All legs brown, with pale knee limited to articulated area. Abdomen with distinct dark brown posterior bands in segment I–VIII. Hypopygium brown in basal section and slightly pale in distal part.

Total length 2.3–2.8 mm, wing length 1.1–1.3 mm.

Head. Frontal tubercles absent. Flagellomere 1–12, 490–500 (n = 2); flagellomere 13, 370– 380 m (n = 2). AR 0.74–0.78 (n = 2). Lengths (μm) of palpomeres (Pm) 1–5: 25–30; 30–35; 90–95; 80–90; 150–165, respectively (n = 2). Temporals 5–6, uniserial. Clypeus with 10–12 setae.

Thorax with distinct scutal tubercle at 1/3 from antepronotum to scutellum. Antepronotals 0; acrostichals 0; dorsocentrals 4–6, sparsely distributed, with 1–2 humerals; tiny humeral pit present. Prealars 0. Scutellum with 2 setae.

Wing ( Fig. 1D View Fig ). Plain, wedge-shaped, anal lobe very reduced. VR 1.29–1.31. Setation: R 0, R 1 0, R 4+5 2–4, squama bare.

Legs ( Figs 1B View Fig , 2D–F View Fig ). Length of fore-leg 4.0– 4.3 mm, c. 7× thoracic height. Fore tibia scale pointed, 30-35 long, subapex of tarsomere IV of fore-leg with 3 aligned stiff setae, 30–35 long. Long spurs of mid and hind combs 55–63 long, curved. LR 1 2.50–2.58, LR 2 0.95–0.98, LR 3 1.22–1.24; BV 1 2.10–2.24, BV 2 2.90–2.96, BV 3 2.46–2.48; SV 1 1.15–1.17, SV 2 2.44–2.52, SV 3 1.82–1.85.

Hypopygium ( Fig. 1G View Fig , 2J–L View Fig ). Anal tergite bands separated medially, with 0 (?1) median seta, 4–6 baso-lateral setae submarginal on tergite IX. Anal point narrow (4 wide at base) parallel-sided to slightly tapering to towards apex, c. 25 long from sclerotised base. Superior volsella ( Fig. 2K View Fig ) curved medially, 25–30 long, with 3 medially-directed setae arising from basal-mid inner margin. Inferior volsella cylindrical, 70 long (inner margin) extending to mid-section of gonostylus, microtrichiose apicoventrally, apically with medially and dorsomedially-directed, simple setae, with 4–6 differentiated posteriorly directed strong seta. Gonostylus c. 50 long, slender, tapering to blunt point. Transverse sternapodeme broadly plate-shaped, bluntly rounded anteriorly, without oral projections. Phallapodeme simple, distinct.

Female, pupa and larva unknown.

Remarks. K. mulu conforms substantially to the male generic diagnosis for Kribiodosis ( Han et al., 2021) but is distinguished from congeners by the legs showing a limited pale ‘knee’, and wing veins R and R 1 totally lacking setae (R 4+5 has few setae). The three stiff setae (‘pseudospurs’) on Ta 4 in the fore-legs ( Han et al., 2021: fig. 4b), are unusual, possibly assisting in copulation. Similar structures in Chironomus claggi Tokunaga, 1964 are located on the mid– and hind leg tarsomeres ( Yamamoto & Yamamoto, 2018), rather than on the fore leg as in Kribiodosis .