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

Hippa, Heikki & Vilkamaa, Pekka, 2007, The flagria group of Keilbachia Mohrig (Diptera, Sciaridae) in a biodiversity hot spot: nine new sympatric species from Kambaiti, Myanmar, Zootaxa 1556, pp. 31-50 : 39-41

Keilbachia fasciata sp. n.

( Figs 1 D, 2C, 3B, 6C, D)

Material studied. Holotype male (in NRMS). N.E. Burma ( Myanmar), Kambaiti, 7000 ft., 28.5.1934, R. Malaise.

Male. Colour. The specimen is strongly faded, almost unicolorous pale yellowish-brown. Head. Eye bridge 2–3 facets wide. Face (prefrons) with ca. 5 setae, the exact number and the arrangement pattern not distinctly seen because the face is laterally compressed and distorted. Clypeus with 1 seta. Maxillary palpus with one palpomere which shows indications of being composed of two elements, with one lateral seta (only sockets left) on the thicker basal part and one, possibly two setae on the narrower apical part, the hyaline sensilla widely scattered on dorsal surface of the basal part, no sensory pit. Antennal flagellomere 4, Fig. 2 C. Thorax. Number of setae on anterior pronotum and episternum 1 not counted because the sclerites are badly distorted in the single specimen. Wing. Length 2.7 mm. Width/length 0.45. R1/R 1.00. c/ w 0.77. r-m much longer than bM, r-m/bM 1.92, r-m with 3 setae, bM non-setose. Legs. Apex of fore tibia, Fig. 3 B. Length of fore basitarsomere/length of fore tibia 0.67. Length of fore tibia/length of fore femur 2.00 (this ratio may be inexact because the basal part of femur cannot be clearly seen). Length of hind tibia/length of scutum+scutellum 2.30. Abdomen. Sternite 8 with ca. 20 setae, widely spread. Hypopygium. Fig. 6 C, D: Gonostylus with ca. 8 long curved mesial megasetae arising from a common basal body and 5–6 megasetae in a row between these and the apical tooth. Tegmen rather simple, subtriangular.

Female unknown.

Discussion. Keilbachia fasciata is similar to K. gigas . Both differ from other similar Keilbachia by having the maxillary palpus one-segmented but with elements of two palpomeres still discernible, and by having the curved megasetae on the gonostylus relatively short and high in number, seven or more instead of six or less. K. fasciata is distinguished from K. gigas by its much smaller size, wing length under 3 mm instead of approximately 4 mm, by having stM longer that the M fork, not shorter, and by having distinct megasetae on the apical part of gonostylus instead of thickened, basally curved, more normal setae.

Figures

FIGURE 1. Maxillary palpus. A, Keilbachia acamptochaeta sp. n. (paratype). B, K. flabellata sp. n. (holotype). C, K. gigas sp. n. (holotype). D, K. fasciata sp. n. (holotype). E, K. foveolata sp. n. (holotype). F, K. bicuspis sp. n. (holotype). G, K. rima sp. n. (holotype). H, K. filigera sp. n. (holotype). I, K. oligonema sp. n. (holotype). Scale 0.10 mm.

FIGURE 2. Antennal flagellomeres 3 and 4 (A) and flagellomere 4 (B – E). A, Keilbachia bicuspis sp. n. (holotype). B, K. oligonema sp. n. (holotype). C, K. fasciata sp. n. (holotype). D, K. filigera sp. n. (holotype). E, K. rima sp. n. (holotype). Scale 0.10 mm.

FIGURE 3. Apical part of fore tibia, prolateral view. A, Keilbachia oligonema sp. n. (Burma). B, K. fasciata sp. n. (paratype). C, K. rima sp. n. (holotype). D, K. acamptochaeta sp. n. (paratype). E, K. flabellata sp. n. (holotype). F, K. foveolata sp. n. (holotype). G, K. filigera sp. n. (holotype). H, K. bicuspis sp. n. (holotype). I, K. gigas sp. n. (holotype). Scale 0.10 mm.

FIGURE 6. Part of hypopygium (A, C) and gonostylus (B, D), ventral view. A, B, Keilbachia filigera sp. n. (holotype). C, D, K. fasciata sp. n. (holotype). Scale 0.10 mm.