Diadocidia sevciki L. PAPP, 2005

Papp, L. & Ševčík, J., 2005, New Taxa Of Diadocidiidae (Diptera) From The Oriental Region, Acta Zoologica Academiae Scientiarum Hungaricae 51 (4), pp. 329-341 : 333-336

Diadocidia sevciki L. PAPP , sp. n.

( Figs 7, 8 )

Holotype male ( HNHM): TAIWAN, Ilan Hsien , Fu-Shan LTER Site, over a rocky brook,

September 26, 2000, leg. L. PAPP .

Measurements (in mm): body length 2.56, wing length 2.88, wing breadth 1.13.

Head and body brown, legs yellow, incl. tarsi, only apical tarsomeres brownish yellow.

Three ocelli, lateral ocelli more than twice larger than median one and separated from the eye margin by a distance of less than 1/3 of their diameter. Scape and pedicel light brown, about as long as wide. Flagellum of 14 flagellomeres (right flagellomeres 9–14 lost), darker brown, cylindrical, densely covered with fine pale cilia. Also base of first flagellomere brown. Ratio of length of flagellomeres 1 to 2 and 3 are 14.5: 9: 8.5, i.e. 0.16, 0.10 and 0.094 mm, width of flagellomere 1 0.05 mm, that of flagellomeres 2–3 almost the same. That is, first flagellomere only slightly more than 3 times longer than broad. Mouthparts and palpi all dark. Four palpomeres, covered with lighter setae. Apical palpomere thin and long, only 0.182 mm long on holotype (dry).

Mesoscutum uniformly dark brown, shiny, with some greyish microtomentum but without any longitudinal stripes. Lateral margins of mesoscutum with long setae. All setae black. Scutellar setae broken off, but bases of 3 pairs of long setae detectable. Anepisternum, preepisternum 2 and metepisternum lighter brown, mediotergite and laterotergite as dark as mesoscutum. Antepronotum with several long setae, longest ones broken off. No anepisternal setae or setulae.

Wings light brownish, veins ochre, both membrane and veins evenly covered with macrotrichia. Costa produced beyond R 5 by a distance of 0.15 mm and ends abruptly. Sc strong, complete, ending in C; ratio of distance on costa from H to Sc and Sc to R 1 0.75. R 1 terminating in C distally to level of base of M-fork. R 4+5 apically downcurved, while slightly S-shaped in D. setistylus PAPP, 2003 . Cross-veins R-M and M-M in one line. M fork with a short stalk, M ratios 0.62, 0.80, i.e. M 2 slightly longer than stalk. In D. setistylus M fork much longer, i.e. M 2 much longer than stalk (54 vs 95). Cu 1 ratio 1.25. M 3 thick to wing margin, Cu 2 distinct to level of M 3 -Cu. A 1 well developed and setose, reaching wing margin. Vein A 2 not discernible. Calypter with several long setae along its margin, up to 0.21 mm. Knob of halteres brown, stalk yellowish.

Legs yellow, covered with evenly set dark trichia and several setae. Male hind coxa in middle third with 4 black setae of 0.2 mm postero-laterally (there is another, more dorsal seta in D. setistylus ). All trochanters with a black spot ventrally. Femora laterally slightly compressed and thickened medially. Ratios of coxae to femora (without trochanter) and to tibia: 48/70/92; 43/86/108; 41/101/144. Mid tibia with 1 anterodorsal, 1 posterodorsal and 1 subventral setae. Hind tibia with 3 long dorsal setae. All spurs on mid and hind tibiae subequal in length, hind ones 0.21 mm, 0.19 mm (measurements taken on holotype). Empodia very small.

Abdomen dark brown, tergites and sternites covered with long dark setae. Male terminalia 0.24 mm long. Tergite 9 ( Fig. 7 ) comparatively small and extremely short, more than twice broader than long (2.33×), edges rounded, with thick long setae, which are more or less ordered in 2 rows (2 lateral setae being the longest). Gonocoxites not large but not slender, meeting on a longer section ventrally. Gonostylus broad at base, horizontally medially curved, with high number of strong setae. The apex of gonostylus is comparatively thick, black and not bifid ( Fig. 8 ); gonostylus in broadest extension (largely in a caudal view), subtriangular. Aedeagal complex rather simple, ventrally curved.

Etymology. I name this new species to the honour of my friend Dr JAN ŠEVČÍK (Silesian Museum, Opava), who has already published numerous and high quality papers on families of Sciaroidea.

Diagnostic characters. This is a peculiar species with its uniapical and strongly setose gonostylus and transverse male tergite 9. Its unicolorous (not striped) dark thoracic scutum is also characteristic. We think, there is no closely related described species in the Oriental region but a similar species, Diadocidia setistylus L. PAPP , was found in Hungary (Mecsek Mts) and described recently est extension (subcaudal view). Scale: 0.1 mm for all

( PAPP 2003), whose gonostylus and tergite 9 are given for comparison ( Figs 9–10 ). The two species differ also in a number of body and wing characteristics, as given above. E.g. M fork of D. sevciki is much longer, i.e. M 2 much longer than stalk (0.594 vs 1.045, ratio 0.568), its male hind coxa in middle third with 4 black setae of 0.2 mm postero-laterally (there is another, more dorsal seta in D. setistylus ).

First we thought to place these two species in the subgenus Adidocidia tentatively. They are not closely related to any other species of Adidocidia but only to each other. This is why we took no notice of subgeneric relegation finally (see the key above).

Figures

Figs 7–10. Diadocidia species, male genitalia. 7–8 = D. sevciki sp. n., holotype: 7 = tergite 9 ventrally, 8 = gonostylus in broadest (i.e. not the longest) extension (subcaudal view); 9–10 = D. setistylus L.PAPP, paratype (Mecsek Mts, Hungary): 9 =tergite 9 ventrally, 10 = gonostylus in broad-