Mesochria thaii L. PAPP, 2006

Papp, L., Merz, B. & Földvári, M., 2006, DIPTERA OF THAILAND A summary of the families and genera with references to the species representations, Acta Zoologica Academiae Scientiarum Hungaricae 52 (2), No. 2, pp. 97-269 : 127-128

Mesochria thaii L. PAPP , sp. n.

( Figs 17–19 )

Holotype male ( HNHM, right mid leg lost, abdomen with genitalia in a plastic microvial with glycerol): THAILAND: Khao Pu – Khao Ya N. P., along a forest brook below the (Pak Yam) waterfall, Nov 21, 2004, No. 42, L. PAPP & M. FÖLDVÁRI.

Measurements in mm: body length 1.96, wing length 2.27, wing breadth 1.30.

Scutum unicolorous ochre, pleura, coxae and legs yellow.

Ocellar triangle much protruding, 0.065 mm high, all ocelli directed forward and laterally, respectively. Ocelli large, lateral ones 0.07 mm, apical 0.075 mm. Antennae black, also palpi and proboscis black. Flagellum of probably 14 flagellomeres, but apical 4 ones lost on holotype. Ventral facettes of eyes smaller than dorsal ones.

Legs unicolorous without any pattern, only apical part of hind tibia darker. Hind coxa with 4 medium-long setae on postero-lateral edge (partly broken on holotype). Length ratios of tibiae and basitarsi: fore: 77: 67 (in paratype of M. simplicipes 79: 67), mid 104: 85, hind 138: 83 (x 0.0109 mm). Hind tibia medially on posteromedial surface with a row of 9 black thick setae. Claws rather long (0.06 mm), thin, curved.

Veins yellow, upper veins, costa and basal setion of Cu1 ochre. Subcostal vein rather long. Sc, R1, R2+3 and R4+5 setose both dorsally and ventrally. M1 and M2 very faint, only apical parts well visible (yellow). M3 almost straight, downcurved apically. The most easily detectable characteristic of this new sp. is that Cu1 vein tenderly curved and not angulately “broken” at middle. Cu2 faint but distinct, detectable even well distally to M-Cu. A1 vein slightly curved in apical half and reaches wing margin but very faint and even disappearing in basal 1/3. A2 present on 2/3 distance of its base to wing margin.

Abdomen rather thick, dark brown. Sternites broad, even the 2 nd one. Tergites 8 and sternite 8 not fused, sternite 8 very short, 0.15 mm only. Tergite 8 0.07 mm, form half of a ring. Cerci ( Fig. 18 ) much different from those of M. simplicipes : longer but less high in profile (cf. Figs 20–21 ). Lateral lobe of gonocoxites broadly rounded, i.e not narrowed apically in profile as in M. simplicipes ( Figs 18–19 cf. Fig. 21 ). Gonostylus bilobed, dorsal lobe black, strongly dorsally curved ( Figs 18–19 ), apical lobe less sharp than in M. simplicipes . Phallus thin, straight, upcurving apically.

The new species is related to M. simplicipes ; the differentiating characters are given in the key below.

A KEY TO THE ORIENTAL SPECIES OF MESOCHRIA ENDERLEIN

1. Mid and hind leg with distinct brown bands on femur and tibia (although they may be diffuse on mid leg). Mesoscutum caudally with 4 large dark brown patches. Posterodorsal row of spiniform setae on hind tibia of ca. 12 setae

M. cinctipes DE MEIJERE, 1913

– Mid and hind leg without brown bands on femur and tibia, only knees and end of tibiae darkened. Mesoscutum without dark patches caudally. 2

2. Hind femur with 9 setae in the posterodorsal row. Distance of apex of R5 and M1 equals that of M1 and M2 on wing margin. Male genitalia as in Figs 17–19. M . thaii sp. n.

– Hind femur with ca. 16 setae in the posterodorsal row. Distance of apex of R5 and M1 shorter than that of M1 and M2 on wing margin. Male genitalia as in Figs 20–21 . Taiwan and Thailand. M. simplicipes L. PAPP, 2006

(The female type of M. intermedia EDWARDS (N Borneo) was not examined within the scope of this project but it does not seem to be closely related to any of the above species.)

Figures

Figs 17–21. Mesochria spp., male genitalia.17–19 =M.thaii sp.n., holotype male:17 =apical part of genitalia, ventral view, cerci removed, 18 = same, lateral view, 19 = whole genitalia, lateral view. 20–21 = M. simplicipes L. PAPP: 20 = caudal view, 21 = lateral view. Scales: 0.2 mm for Figs 19–21,