Elaphropeza lowioides, Grootaert & Shamshev, 2015

Grootaert, Patrick & Shamshev, Igor, 2015, New species of fast-running flies (Diptera: Empidoidea, Hybotidae, Tachydromiinae) from mangroves in Singapore, Raffles Bulletin of Zoology 63, pp. 583-609 : 595-597

Elaphropeza lowioides , new species

( Figs. 22–25 )

Material examined. Holotype male: Singapore: Semakau Island , SMN3, 24 May 2012, mangrove, (reg. 29250, Ma0824) . Paratype: Semakau Island , 1 female, SMN1, 12 July 2012, mangrove, (reg. 29339, Ma6788) .

Etymology. The epithet refers to its resemblance to E. lowi Grootaert & Shamshev, 2012 .

Diagnosis. Species of the E. ephippiata group; recognised by entirely yellow thorax, antenna with postpedicel about 3 times as long as wide, legs yellow with only tarsomere 5 brown, hind tibia with 1 anterodorsal bristle, haltere yellow.

Description. Length: wing 1.8 mm.

Male: Occiput entirely black, largely shining; with yellowish setation; inner verticals long inclinate, outer verticals hardly prominent. Anterior ocellars long proclinate, posterior ocellars minute. Frons shining, very narrow, above antennae about as broad as anterior ocellus. Antenna with scape and pedicel yellow, postpedicel somewhat darker toward apex, stylus brownish; pedicel with circlet of subequally short setulae; postpedicel short, 3.3 times longer than wide; stylus with short pubescence, moderately long, 1.5 times longer than postpedicel. Proboscis brownish yellow. Palpus yellow, small, rounded, bearing scattered setulae, subapical seta hardly prominent.

Thorax entirely yellow, shining, with brownish yellow longer setae. Prothoracic episterna lacking long upturned seta just above fore coxa, with minute setula on upper part. Postpronotal seta hardly prominent. Mesonotum with 2 long notopleurals, 1 similar postsutural supra-alar, 1 similar postalar and 4 scutellars (apical pair very long, cruciate; lateral pair minute); acrostichals short, arranged in 4 rows, hardly separated from dorsocentrals, lacking on prescutellar depression; dorsocentrals multiserial, sparser toward scutellum, 1 prescutellar pair very long.

Legs robust, almost entirely yellow, only tarsomere 5 of all legs brownish. Coxae and trochanters with unmodified setation. Fore femur thickened, with hardly prominent rows of anteroventral and posteroventral setulae and long seta near base, no subapical seta anteriorly. Fore tibia lacking prominent bristles (except subapicals). Mid femur with row of minute anteroventral and row of longer posteroventral spinules, 1 long seta near base and 1 long subapical seta anteriorly. Mid tibia with black ventral spinules and 1 subapical claw-like spine, lacking prominent setae (except subapicals). Hind femur with hardly prominent anteroventrals and 3 erect dorsal setae near base. Hind tibia with 1 moderately long brownish anterodorsal bristle on about middle; apical projection small, rounded, brownish. Tarsi of all legs unmodified, with unmodified setation.

Wing normally developed, finely infuscate, covered with uniform microtrichia; veins mostly yellowish brown, basal section of M 1+2, crossveins bm-cu and r-m pale. Costal vein with moderately long, uniform setulae along anterior margin. Costal bristle long, brown. Costal index: 29/25/24. Vein Rs long, slightly longer than crossvein bm-cu. Vein R 2+3 evenly bowed. Veins R 4+5 and M 1+2 divergent near wing apex, R 4+5 slightly bowed, M 1+2 straight. Vein CuA 1 reaching wing margin. Vein A 1 lacking. Crossvein bm-cu perpendicular. Crossvein r-m somewhat before middle of cell bm. Haltere pale yellow.

Abdomen. Tergite 1 almost entirely pale yellow; tergites 2–3 brownish yellow, subtriangular viewed laterally, divided medially, with scattered unmodified setae; tergite 4 dark brown, broadest, shining, without squamiform setae, with several moderately long pale setae on each side; tergite 5 dark brown, very narrow, undivided, with squamiform setae; tergites 6–7 brownish yellow, with rather long posteromarginal setae; tergite 8 unmodified. Sternites yellowish to brownish yellow, with scattered minute setulae, sternite 8 with rather short posteromarginal setae. Gland-like structure present between tergites 4–5.

Terminalia ( Figs. 23–25 ) moderately large, with left surstylus brownish, otherwise yellow. Right epandrial lamella triangular with rounded tip, with 3 subapical spine-like black bristles on the inner side ( Fig. 23 ). Right and left cercus fused, large protruding from epandrial lamellae, conical without folds or extensions ( Fig. 24 ). Left epandrial lamella with 4 bristles. Left surstylus large with a few longer bristles at base, otherwise with minute bristles ( Fig. 25 ).

Female: Similar to male.

Distribution. Singapore.

Remarks. Elaphropeza lowioides , new species belongs to a complex of six species: E. chanae Grootaert & Shamshev, 2012 , E. chanoides , new species, E. gohae Grootaert & Shamshev, 2012 , E. lowi Grootaert & Shamshev, 2012 and E. malayensis Shamshev & Grootaert, 2007 . Externally they are difficult to distinguish, and the male genitalia should be checked if possible.

In the key to Elaphropeza of Singapore ( Grootaert & Shamshev, 2012) this species complex runs to couplet 71 (small yellow species with scutum and scutellum entirely yellow, with yellow legs with only tarsomere 5 brown to black, acrostichals lacking on the prescutellar depression and white halteres).

A modified key is proposed to this complex because the original couplet 71 enquires if the length of the postpedicel is 3.3 to 4.0 times as long as wide versus postpedicel nearly 3 times as long as wide. Though this character is correct, it is difficult to use.

71. Male fore tibia with a subapical spine or spine-like bristle... ............................................................................................ 71a

– Male fore tibia without subapical spine or spine-like bristle. ............................................................................................71d

71a. Antennal stylus nearly as long as postpedicel ..................71b

– Antennal stylus longer than postpedicel, about 1.5 times as long..................................................................................... 71c

71b. Right epandrial lamella with 4 brown to black subapical spinelike bristles on inner side (Fig. 137 in Grootaert & Shamshev, 2012). Left surstylus triangular (Fig. 139).............................. ................................ E. chanae Grootaert & Shamshev, 2012

– Right epandrial lamella with only 3 pale flattened subapical bristles ( Fig. 17 ). Left surstylus narrower ( Fig. 19 ) ............... ....................................................... E. chanoides , new species

71c. Right epandrial lamella with 3 subapical spine-like bristles ( Fig. 23 ). Left cercus large, triangular, tip pointed ( Fig. 24 ). ........................................................ E. lowioides , new species

– Right epandrial lamella without subapical spine-like bristles. Tip of left cercus with an extension........................................ .................................. E. gohae Grootaert & Shamshev, 2012

71d. Right epandrial lamella with elbow-like bowed apex bearing 3 black spine-like bristles (Fig. 133 in Grootaert & Shamshev, 2012.................. E. malayensis Shamshev & Grootaert, 2007

– Right epandrial lamella with broadened apex without black spine-like bristles (Fig. 145).................................................... ..................................... E. lowi Grootaert & Shamshev, 2012

Figures

Fig. 22. Elaphropeza lowioides, new species, male habitus lateral. Genitalia removed and illustrated in Figs. 23–25.

Figs. 23–25. Elaphropeza lowioides, new species: 23, right epandrial lamella, lateral view; 24, epandrium with cerci, dorsal view; 25, left surstylus, lateral view. Scale bar = 0.1 mm.

Figs. 17–19. Elaphropeza chanoides, new species: 17, right epandrial lamella, lateral view with detail of subapical bristles; 18, epandrium with cerci, dorsal view; 19, left surstylus, lateral view. Scale bar = 0.1 mm.