(Figs. 37–52, 55)

Type locality. Malaysia, Perak, Hulu, Belum Camp (5°30′07″N, 101°26′21″E).

Type material. HOLOTYPE: J (NMLS), MALAYSIA: PERAK: Hulu, Belum Expedition, Belum Camp, iv.–vi.1994, light trap (Rothamsted). Slide, Canada Balsam. PARATYPES: 4JJ (NMPC: Cat No.34500–34503, Inv. No. 17662–17665), the same locality and data, dissected. The figures are based mainly on the holotype.

Description. Male. Head prolonged (Fig. 37), vertex conspicuously enlarged, almost hemisphaerical, hairy. Eyes separated by 1.6 diameters of one facet (Fig. 38), margins of median eye extensions parallel in ventral part, divergent dorsally, eye bridge consisting of four facet rows, near frontal suture only three facets in dorso-ventral line on both sides. Interocular suture moderately convex, with very small triangular patch dorsally. Sockets of side setae in two rows above dorsal margins of eyes. Frontoclypeus with oval patch of hair insertions, upper area of patch with narrow stripe of hairs touching frontal suture. Antennae (Figs. 39, 46, 47) with 16 antennomeres. Scape rather short, widened distally, 2.3 times as long as pedicel, the latter almost globular. Flagellomeres excentrically bulbous with rather long and broad necks, antennomere 16 with slender, digitiform part. Ascoids of flagellomeres needle-shaped, long, bent, paired. Length ratios of maxillary palpomeres equal to 1: 1.7: 1.5: 1.3. Palpomere 4 annulate (Fig. 49), connected basally with apical area of palpomere 3. Labium and labial lobes as in Fig. 40. Labrum enlarged (Fig. 37), hairs widely spaced. Cibarium with simple margins, 2.4 times as long as epipharynx (Fig. 48).

Thoracic sclerites as in Fig. 41. Haltere almost bare (Fig. 42), only several setae developed. Wing narrowly lancet shaped (Fig. 55), 2.1 – 2.3 mm long (2.2 mm in the holotype), wing membrane bare, clear, radial and medial forks complete. Basal costal nodes distinct. Costal vein depressed near end of Sc, the latter hardly approximated to R 1 before end, long linear streak running parallel to R 1 developed. Bases of M 3, M 4 and Cu not connected. Radial fork of wing placed behind medial fork, the latter a little behind end of Cu. End of R 4 in acute apex of wing, R 5 extending distally and reaching wing margin below apex. Insertions of hairs in place of veins r-r, r-m and m-m not developed. The following veins or their parts strengthened: Sc proximally and distally, middle part of R 2+3, whole R 5, M 4 and Cu. Medial wing angle 162° (BCD). Wing 2.5 times as long as wide. Length ratios of femur, tibia and first tarsomere: P 1 = 2.4: 2.3: 1, P 2 and P 3 completely missing. Fore claws as in Figure 43.

Basal apodeme of male genitalia spatula-shaped and straight in dorsal view, narrowed and rounded proximally, very narrow and slightly S-shaped in lateral view. Aedeagal complex (Figs. 51, 52) in comparison with gonocoxites longer, caudal part of aedeagal complex narrowed in dorsal view and widened and rounded in lateral view, paired lateral minute protuberances of aedeagal complex developed. Gonocoxites cylindrical (Figs. 50, 51), a little bent, gonostyli longer, gradually tapering but before apex narrowed, abruptly curved and apically pointed. Epandrium almost bare (Figs. 44, 45), several insertions of hairs caudally on both sides of a deep epandrial notch. Central aperture developed. Remainders of tergite 10 and sternite 10 inside epandrium not visible. Hypandrium largely expanded in middle, bare (Figs. 51, 52). Hypoproct large, almost circular, twice as long as epiproct (Figs. 44, 45), the latter small, short, almost triangular, tongue-shaped, both parts hairy. Surstyli before tip rapidly narrowed and a little bent; number of retinaculi 11–12, area of insertions of retinaculi large, conspicuously prolonged.

Female unknown.

Differential diagnosis. Perakomyia sifneri sp. nov. is characterized by two rows of insertions of sensory setae above the upper margins of eyes (Fig. 37), scape 2.3 times as long as pedicel (Fig. 46), simple margins of cibarium (Fig. 37), longer aedeagal complex in comparison with the gonocoxites, narrowed caudal part of the aedeagal complex in dorsal view, developed paired lateral minute protuberances of the aedeagal complex (Figs. 51, 52), rapidly narrowed and a little bent surstyli before the apex (Figs. 44, 45) and the presence of 11–12 retinaculi. Perakomyia kalabakensis (Quate, 1962) comb. nov. differs from the new species by only one row of insertions of sensory setae above the eyes, scape 3.7 times as long as pedicel, conspicuously strengthened margins of cibarium, aedeagal complex as long as or shorter than the gonocoxites, caudal part of the aedeagal complex not narrowed, absent paired lateral minute protuberances of the aedeagal complex, gradually tapering, almost straight surstyli and only eight retinaculi.

Etymology. The species is dedicated to my friend František Šifner (Praha, Czech Republic), a specialist in Diptera, Scathophagidae.

Bionomy. Unknown. The males were collected at light in a primeval rainforest.

Distribution. Peninsular Malaysia: Perak state.