Keilbachia mirabilis, Hippa, Heikki & Vilkamaa, Pekka, 2007

Hippa, Heikki & Vilkamaa, Pekka, 2007, New species and records of Keilbachia Mohrig (Diptera, Sciaridae) from the Oriental region, Zootaxa 1622, pp. 57-68 : 64-66

Keilbachia mirabilis sp. n.

Fig. 5 A–F.

Material studied. Holotype male. MALAYSIA, Selangor, University of Malaya Field Study Centre, 800 ft., Malaise in jungle, 24.2.– 14.3. 1997, H. Hippa, M. Jaschhof & B. Viklund (in NRMS). Paratypes. 3 males with same data as holotype and 1 male with same data but dated 2.–8.3. (in NRMS); 1 male, MALAYSIA, Pahang, Genting Highlands, Awana, Malaise trap, 10.– 22.3.1997, H. Hippa, M. Jaschhof & B. Viklund (in NRMS).

Male. Colour. Almost unicolorous brown, maxillary palpus and legs paler brown than the other parts, abdomen slightly paler than thorax, wing hyaline brownish, haltere pale brown. Head. Eye bridge 2–4 facets wide. Face (prefrons) with 4–10 setae, which are widely spread, but in the one case with 4 setae that are in a transverse ventral row. Clypeus with 1–2 setae. Maxillary palpus, Fig. 5 A: with 3 palpomeres. Palpomere 1 with 1 seta, the hyaline sensilla widely scattered on the dorsal surface, no sensory pit. Palpomere 2 with 4–6 setae. Palpomere 3 with 4–6 setae. Antennal flagellomere 4, Fig. 5 B. Thorax. Anterior pronotum with 2 setae. Episternum 1 with 3–5 setae. Wing, Fig. 5 D. Length 0.85–0.95 mm. Width/length 0.45–0.50. R1/R 0.40– 0.55. c/ w 0.50 –0.60. r-m and bM approximately equal in length, r-m/bM 0.85–1.15. Legs. Apex of fore tibia, Fig. 5 C. Length of fore basitarsomere/length of fore tibia 0.45–0.50. Length of fore tibia/length of fore femur 1.05–1.15. Length of hind tibia/length of scutum+scutellum 1.45–1.50. Abdomen. Sternite 8 with 4–5 setae in a transverse row on posterior part. Hypopygium Fig. 5 E, F: Gonostylus with the curved megaseta extremely long, longer than the gonostylus itself, without other megasetae and without an apical tooth. Tegmen with strong lateral shoulders, the part posterior to the shoulders long and narrow.

Female unknown.

Discussion. Keilbachia mirabilis is the third known Keilbachia with only one curved mesial megaseta which lacks additional megasetae on the gonostylus. The other two species that are similar in this respect are K. adunca and K. clinata . From both of these, K. mirabilis differs by its smaller size, the wing length being less than one millimetre instead of more than one millimetre, and by its exceedingly long gonostylar megaseta. K. curvispina Edwards from Sumatra is also similar. It is small, as K. mirabilis , but subapically on the gonostylus it has a long seta, which is somewhat intermediate between a megaseta and an unmodified seta. The curved megaseta on the gonostylus in K. curvispina is only half the length of the gonostylus and, unlike K. mirabilis , it has a very long basal body, nearly as long as the megaseta.

Figures

FIGURE 5. Keilbachia mirabilis sp. n. (B, C, E, F holotype, A, D paratypes). A: Maxillary palpus, dorsal view. B: Antennal flagellomere 4, ventral view. C: Apical part of tibia 1, prolateral view. D: Wing, dorsal view. E: Part of hypopygium, ventral view. F: Gonostylus, ventral view. Scale 0.05 mm, for D 0.5 mm.