Keilbachia fratercula, Vilkamaa, Pekka, Hippa, Heikki & Mohrig, Werner, 2011

Vilkamaa, Pekka, Hippa, Heikki & Mohrig, Werner, 2011, The genus Keilbachia Mohrig (Diptera, Sciaridae) in New Caledonia, with the description of five new species, Zootaxa 2771, pp. 53-61 : 60

Keilbachia fratercula sp. n.

Figs 5 A–E

Material studied. Holotype. Male. NEW CALEDONIA, Pointe de Cagou, 166°20’ E, 21°20’S, 30 m, humid forest, 5–8.ix.1984, Tillier & Bouchet (in MNHN). Paratypes. 1 male, same data as holotype (in SMNH); 2 males, Ouinné Valley, 730 m, 166°28’E, 22°02’S, humid forest with araucarians, 27–30.x.1984, Tillier & Bouchet (1 in MZH, 1 in PWMP).

Description. Male. Head. Brown, maxillary palpus very pale brown, antenna brown. Eye bridge 3–5 facets wide. Face with 8–10 setae. Clypeus with 1–3 setae. Maxillary palpus with 3 palpomeres, first and third palpomeres subequal in length, or second palpomere longer; first palpomere with 1 long sharp seta, with dorsal patch of sensilla; second palpomere with 1 long sharp seta and 4 shorter truncate setae, third palpomere with 4 short truncate setae. Antennal flagellomere 4, Fig. 5 A: 2.25–2.95x as long as wide, neck longer than wide, longest setae longer than width of flagellomere. Thorax. Brown, pleura slightly paler than scutum, setae dark. Anterior pronotum with 2 setae. Episternum 1 with 3–5 setae. Wing. Length 1.1–1.5 mm. Width/length 0.45–0.50. R1/R 0.60–0.75. c/ w 0.60 –0.75. r-m and bM faded in specimens, lengths not seen, both r-m and bM nonsetose. Haltere pale brown. Legs. Pale yellowish brown. Apical part of front tibia, Fig. 5 B: tibial organ with fine and pale vestiture, in shallow depression, forming a patch. Front tibial spur slightly longer than tibial width. Abdomen. Pale brown, paler than thorax, setae dark. Hypopygium, Figs 5 C–E: pale brown, as abdomen. Gonocoxa and gonostylus of equal length. Ventral setosity of gonocoxa sparse. Gonostylus elongated, slightly narrowed towards blunt apex, mesial side slightly impressed; setosity sparse, apically denser with some slender truncate modified setae among ordinary setae; without apical tooth, subbasally with curved megaseta. Tegmen slightly wider than long, with sharp basolateral shoulders, aedeagus short.

Discussion. See under Keilbachia truncata .

Remarks. The New Caledonian Keilbachia species are very similar, and resemble most of all the New Guinean K. indigena , in lack of the subapical-apical megasetae on the gonostylus, and in having a medium-long subbasal megaseta in a relatively basal position on the gonostylus and a strongly modified tegmen with well-developed lateral shoulders. Subapical megasetae are also lacking in some Oriental Keilbachia ( K. adunca Hippa & Vilkamaa , K. clinata Hippa & Vilkamaa , K. mirabilis Hippa & Vilkamaa ), or the megasetae are slender in some species, but in any case not exactly like the hyaline setae on the gonostyli of K. constricta , K. fratercula and K. truncata from New Caledonia. Of all the oriental species, K. adunca is most similar to the Australasian species, having a gonostylus and tegmen of similar type, and presumably forms with them a monophyletic group.

Figures

FIGURE 5. Keilbachia fratercula sp. n. (A, E paratype from Ouinné Valley, B paratype from Pointe de Cagou, C, D holotype). A. Antennal flagellomere 4, lateral view. B. Apical part of front tibia, prolateral view. C. Part of hypopygium, ventral view. D. Gonostylus, ventral view. E. Apical part of gonostylus, ventral view. Scale 0.1 mm.