Keilbachia gigas, 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 : 45

Keilbachia gigas sp. n.

( Figs 1 C, 3I, 4C, 8A, E, F)

Material studied. Holotype male (in NRMS). N.E. Burma ( Myanmar), Kambaiti, 7000 ft., 23.4.1934, R. Malaise.

Male. Colour. Head brown, palpus and antennal flagellum pale brown, palpus darker than flagellum. Thorax brown, the middle part of pleura a little paler, a large darker brown patch laterally on metanotum. Legs pale brown, middle and hind coxae with a darker brown patch posteroventrally, apical part of basitarsomere and tarsomeres 2 and 3 darker than other parts of legs. Wing brown. Haltere pale brown. Abdomen pale brown. Head. Eye bridge, Fig. 8 A: 2–4 facets wide. Face (prefrons) with 8 setae in two transverse rows. Clypeus with 1 seta. Maxillary palpus ( Fig. 1 C) with one palpomere which shows indications of being composed of two elements, with 1 lateral seta on the thicker basal part and 3–4 setae on the narrower apical part, the hyaline sensilla widely scattered on dorsal surface of basal part, no sensory pit but the surface with several slight depressions at the sensilla. Antennal flagellomeres rather inflated in the single specimen, and flagellomere 4 not drawn but in a non-inflated condition probably a little more than twice as long as broad. Thorax. Anterior pronotum with 8 setae. Episternum 1 with 11 setae. Wing, Fig. 4 C. Length 3.90 mm. Width/length 0.42. R1/R 0.96. c/ w 0.82. r-m much longer than bM, r-m/bM 1.94, r-m with 7 setae, bM non-setose. M fork unusually long, longer than stM, the base extending more basad than the meeting point of R1 and C. Legs. Apex of fore tibia, Fig. 3 I. Length of fore basitarsomere/length of fore tibia 0.75. Length of fore tibia/length of fore femur 1.53. Length of hind tibia/length of scutum+scutellum ca. 2.00. Abdomen. Sternite 8 with ca. 40 setae, widely spread. Hypopygium. Fig. 8 E, F: Gonostylus with ca. 8 long curved mesial megasetae arising from a common basal body and 2 megasetae at the middle between the former and the apical tooth, near the base of the apical tooth with 2–3 thick setae deviating from the general setosity and two of which are curved in basal part. Tegmen rather simple, subtriangular.

Female unknown.

Discussion. Keilbachia gigas is similar to K. fasciata . For their distinguishing characters, see under the latter. K. gigas is the largest known Keilbachia and, unlike the other species, it has stM shorter than the M fork.

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 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 4. Wing, dorsal view. A, Keilbachia flabellata sp. n. (holotype). B, K. foveolata sp. n. (holotype). C, K. gigas sp. n. (holotype). D, K. rima sp. n. (paratype). Scale 1.0 mm.

FIGURE 8. Eye bridge (A, B), frontal view, part of hypopygium (C, E) and gonostylus (D, F), ventral view. A, E, F, Keilbachia gigas sp. n. (holotype). B, C, D, K. foveolata sp. n. (B, D, E holotype, C non-type). Scale 0.10 mm.