Keilbachia ancylonema, 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 : 60-61

Keilbachia ancylonema sp. n.

Fig. 2 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. 4 males with same data as holotype (in NRMS). Other material. 1 male, N.E. MYANMAR ( BURMA), Kambaiti, 2000 m, 14.5.1934, R. Malaise (in NRMS).

Male. Colour. Almost unicolorous pale brown, maxillary palpus and legs paler brown than the other parts, scutum paler anteriorly at dorsocentral setae, abdomen slightly paler than thorax, wing hyaline pale brownish, haltere pale brown. Head. Eye bridge 4–5 facets wide. Face (prefrons) with 8–12 setae, which are widely spread. Clypeus with 1–2 setae. Maxillary palpus, Fig. 2 A: with 3 palpomeres. Palpomere 1 with 1–3 setae, the hyaline sensilla widely scattered on the dorsal surface, no sensory pit. Palpomere 2 with 6–7 setae. Palpomere 3 with 5–6 setae. Antennal flagellomere 4, Fig. 2 B. Thorax. Anterior pronotum with 2 setae. Episternum 1 with 3–5 setae. Wing similar to Fig. 5 A. Length 1.25–1.40 mm. Width/length 0.45. R1/R 0.50–0.65. c/ w 0.65 –0.85. r-m and bM approximately equal in length, r-m/bM 0.80–1.05. Legs. Apex of fore tibia, Fig. 2 C. Length of fore basitarsomere/length of fore tibia 0.45–0.50. Length of fore tibia/length of fore femur 1.25–1.35. Length of hind tibia/length of scutum+scutellum 2.05, calculated only for one of the paratypes. Abdomen. Sternite 8 with 8–9 setae in a transverse row on posterior part, in a few cases the most lateral seta placed more anteriorly. Hypopygium Fig. 2 D, E, F: Gonostylus with the curved megaseta about half the length of gonostylus, its basal body like a long crest on the mesial side of gonostylus, on the lateral side short, not longer that the socket of the seta. At middle between the curved megaseta and the apex of gonostylus with a rather small megaseta and subapically with two close-set megasetae which do not deviate much from the nearby more normal setae; gonostylus without an apical tooth. Tegmen with strong lateral shoulders.

Female unknown.

Discussion. The Myanmar specimen is very pale because of treatment in KOH. It has the setae of the gonostylus shorter than in those from the type locality, but otherwise it is similar. K. ancylonema is similar to K. camptonema but is distinguished by having the megasetae on the apical half of gonostylus much weaker, their thickness being only about half that of K. camptonema . Furthermore, K. ancylonema is larger than K. camptonema , with a wing length ca. 1.3 mm or more compared with ca. 1 mm or less, and the tegmen has more strongly pronounced lateral shoulders. K. ancylonema and K. camptonema resemble many other Oriental Keilbachia which have one curved megaseta on the gonostylus and have additional megasetae in a more apical position. These are K. aculeata Vilkamaa & al., K. apprima Vilkamaa & al., C. arcuata Vilkamaa & al., K. arrecta Vilkamaa & al., K. curvispina Edwards , K. demissa Vilkamaa & al., K. flagrispina Mohrig , K. mira Vilkamaa & al., K. scutica Vilkamaa & al., K. tenuicula Vilkamaa & al., and K. tenerrima Menzel. Both K. ancylonema and K. camptonema differ from all of these by having a megaseta on the gonostylus almost at the middle between the curved megaseta and the gonostylar apex, and from all of these except for K. curvispina by having the megasetae on the apical half of gonostylus slender instead of short and conical. In K. curvispina there is only one megaseta additional to the curved one; it is placed subapically, is long and slender, and does not deviate very much from nearby unmodified setae. K. ancylonema also resembles K. indigena Mohrig from New Guinea. Unlike K. ancylonema , the latter lacks three megasetae in the apical part of the gonostylus and has the eye bridge 6–7 facets wide instead of 4–5 facets wide.

Figures

FIGURE 2. Keilbachia ancylonema sp. n. (E holotype, A, B, C, D paratype, F from Myanmar). A: Maxillary palpus, dorsal view. B: Antennal flagellomere 4, ventral view. C: Apical part of tibia 1, prolateral view. D: Part of hypopygium, ventral view. E, F: Gonostylus, ventral view. Scale 0.10 mm.

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.