Chersodromia bulohensis, Grootaert & Shamshev, 2012

Grootaert, Patrick & Shamshev, Igor V., 2012, The fast-running flies (Diptera, Hybotidae, Tachydromiinae) of Singapore and adjacent regions, European Journal of Taxonomy 5, pp. 1-162 : 25-28

Chersodromia bulohensis sp. nov.

Figs 31-36

Diagnosis

Occiput pale yellowish in ground-colour; stylus dorsoapical; no distinct vertical bristles; thorax with anepisternum (= mesopleuron) and anepimeron (= pteropleuron) pale brown, katepisternum (= sternopleuron) white; wing with cell br slightly longer than cell bm; hind tibia with only 3 bristles in apical half.

Description

Male LENGTH. Body 1.4 mm; wing 1.0 mm.

HEAD. ( Fig. 31 ) With occiput dark yellowish in ground-colour; face, gena, palpus and proboscis pale yellow, ocellar tubercle brown; eyes black; with yellowish setation. Frons broadly triangular; in front view as wide as pedicel. Eyes almost touching on face; ommatidia enlarged anteriorly and on lower half of eye. Face linear. Ocellars long, as long as postpedicel. Occiput concave above neck; verticals reduced, not prominent, probably two pairs of minute bristles present. Gena broad. Antenna uniformly yellow; pedicel with long ventral seta; postpedicel about as long as pedicel, with rather long slender dorsoapical extension; stylus dorsoapical, at least 4.0 times as long as basal antennomeres combined. Palpus small, white, fusiform with longer pale subapical seta and some setulae.

THORAX. Pale yellow in ground-colour; mesonotum with faint pattern: anterior third with brown median vitta connected near middle with broad brown area at each side, leaving postpronotal lobes, sides of notopleural and prescutellar depressions yellow; pleura with anepisternum and anepimeron yellow, katepisternum and meron (= hypopleuron) almost white; setation yellowish. Postpronotal lobe with 1 long inclinate bristle. Mesonotum with 1 short presutural supra-alar, 2 notopleurals, 1 postsutural supraalar, 1 postalar and 4 scutellars (apical pair long, lateral pair minute); acrostichals reduced, 3 setulae on one line; 3 long dorsocentrals.

LEGS. Pale yellow. Fore femur thickened; with row of short brown posteroventral bristles and long ventral bristles near base. Fore tibia with distinct ventral subapical bristle. Mid femur half as stout as fore femur, with long pale ventral bristle near base and strong brown anterior subapical bristle. Mid tibia with some spinule-like setae on apical half and long posteroventral subapical bristle. Hind femur stouter than mid femur, with very long fine basal ventral bristle. Hind tibia ( Fig. 33 ) with 3 brown bristles slightly longer than wdith of tibia (1 anterodorsal, 1 dorsal and 1 anterodorsal preapical).

WING. ( Fig. 32 ) Normally developed, faintly yellowish tinged, with largely pale brown veins, R 2+3 darker. Costal bristle rather short, brown. Vein Rs rather long, nearly 2.0 times as long as crossvein bm-cu. R 2+3 very short, only slightly longer than distal portion of R 1 (between Rs and meeting point with costa), meeting costa before middle of wing. M 1+2 curving anteriorly just before ending near wing tip. Crossvein bm-cu strongly oblique. Crossvein r-m slightly beyond cell bm. Anal vein absent. Calypter minute. Halter with dusky knob.

ABDOMEN. Yellowish white, with short pale setation; no gland-like structures.

TERMINALIA. Elongate ( Figs 34-36 ), largely yellow, hypandrium brown. Cerci with unmodified setation. Epandrium completely divided. Right epandrial lamella with strong apical seta. Right surstylus not prominent. Left epandrial lamella fused with hypandrium, bearing several short setae apically. Left surstylus consisting of 2 lobes; lower lobe short, elongate oval, with several short, unmodified setae; upper lobe bearing 3 apical spines and 1 long seta near middle mounted on tubercle ( Fig. 36 ). Phallus short. Two rod-shaped apodemes present.

Female Unknown.

Material examined

Holotype ♂

SINGAPORE: Sungei Buloh, 9 December 2002, sweep netting along border of mangrove (reg. 22057, leg. P.G.; in ZRC).

Etymology

The name refers to the type locality Sungei Buloh.

Distribution

Singapore.

Habitat and seasonal occurrence

This species was collected on the edge of mangroves with a single record in early December. Remarks

Chersodromia bulohensis sp. nov. belongs to the species groups with a faint pattern on the scutum and a strong curved seta on the left dorsal surstylus. Additionally, the spines on the left surstylus are stronger than in C. flavicaput Grootaert, Cumming & Shamshev ( Figs 37-40 ), the cerci are larger, and the hind tibia bears 3 long bristles.

Figures

Figs 31-36. Chersodromia bulohensis sp. nov., ♂. 31. head, lateral view. 32. wing, dorsal view. 33. hind femur and tibia, anterior view. 34. right epandrial lamella, lateral view. 35. epandrium with cerci, dorsal view. 36. hypandrium with detail of left surstylus, ventral view.

Figs 37-40. Chersodromia flavicaput Grootaert, Cumming & Shamshev, 2007, ♂ terminalia. 37. hypandrium with phallus, ventral view. 38. tip of hypandrium, ventral view. 39. epandrium with cerci, dorsal view. 40. left epandrial lamella and hypandrium, lateral view. Scale bars = 0.1 mm (after Grootaert et al. 2007).