Syndyas singaporensis, Grootaert & Yang, 2009

Grootaert, Patrick & Yang, Ding, 2009, A New Syndyas Loew, 1857 (Diptera: Hybotidae: Hybotinae) From Mangroves In Singapore, With A Review Of The Oriental And Australasian Species, Raffles Bulletin of Zoology 57 (1), pp. 17-24 : 21-23

publication ID	https://doi.org/ 10.5281/zenodo.4508192
DOI	https://doi.org/10.5281/zenodo.4508847
persistent identifier	https://treatment.plazi.org/id/361887C0-FFE1-7E3E-44E1-9AC853750A5A
treatment provided by	Carolina
scientific name	Syndyas singaporensis
status	sp. nov.

Treatment

Syndyas singaporensis , new species

( Figs. 1 View Figs , 5 View Figs , 9 View Figs , 13 View Fig )

Material examined. – Holotype male: SINGAPORE: Sungei Buloh , 7 Sep.2005, Malaise trap 1 (25336, leg. P. Grootaert, Si 1055, in ZRC of Raffles Museum, NUS, Singapore).

Paratypes: SINGAPORE, 1 female same provenance as holotype. Sungei Buloh, mangrove : 1 male, 1 female, 9 Dec.2002 (22057, Si301); 1 male, 1 Jun.2005 (25165, Si1639); 1 male, 22 Jun.2005 (25171, Si823; on pin, genitalia dissected); 1 male, 1 female, 6 Jul.2005 (25199, Si881); 1 male, 1 female, 20 Jul.2005, (25264, Si1056); 1 male, 27 Jul.2005 (25272, Si289); 1 female, 7 Sep.2005 (25264, Si1056); 1 female, 27 Nov.2003, sweeping (23092, Si92); 1 female, 13 Jan.2006 (26015, Si 1581, RBINS). Chek Jawa, Pulau Ubin, mangrove , 1 male, 1 female, 19 Nov.2002, sweeping (leg. P. Grootaert, RBINS) .

Diagnosis. – Species with brown wing and brown stigma. Discal cell almost as long as basal cells. Mesonotum anteriorly shining black. Hind femur club-shaped, ventrally with spine-like bristles.

Description. – Male: Length: 3.0– 3.2 mm, wing 3.0– 3.2 mm.

Head. Eyes holoptic, frons and face linear. A pair of proclinate ocellars as long as all antennal segments together. Postoculars short, black, with tips proclinate over the eye. Antenna black, third segment elliptical 3 times as long as wide. Arista bare, 3 times as long as antennal segments together. Palp elongate, black with a long black dorso-apical bristle.

Thorax black in ground-colour. Mesonotum shining black on apical half, posterior half thinly covered (subshining) with thin brownish dusting. Humeri brownish (paler than rest of mesonotum). Pleura grey dusted. Large thoracic bristles brown. Acrostichals long, biseriate; dorsocentrals uniseriate but with numerous hairs at sides. A pair of long brown apical scutellars and a series of shorter marginal hairs on both sides.

Legs. Anterior four legs shining brownish black; posterior pair intensively black. Fore coxa with short black hairs anteriorly. Fore femur without ventral bristles, a few fine black posteroventrals near tip. Fore tibia ( Fig. 5 View Figs ) slightly spindle shaped with a very prominent opening of the tibial gland in the form of a tubercle, bearing a hair-like structure at tip; with a row of long posteroventrals, a little longer than tibia is wide; the row continues on fore tarsomere 1. Fore basal tarsomere with some long dorsal bristles, especially a basal one and a pair of apicals. Following tarsomeres also with distinct dorsal hairs. Mid femur ventrally bare. Mid tibia with 4–5 black dorsal bristles, 3 times as long as tibia is wide and a very long ventral preapical; a row of long brown posteroventrals. Mid basal tarsomere with two long dorsals and a row of long posteroventrals and a very long ventral near base. Hind femur ( Fig. 9 View Figs ) club-shaped, slender on basal half, gently widening towards tip, near tip about 1.5 times as wide as at base. Ventrally with a row of equally long spine-like bristles, in basal half the spines are a little longer than femur is wide; in apical half about as long as femur is wide. Hind tibia club-shaped, narrow at base but abruptly widening towards tip, at its widest part, 3 times as wide as at base ( Fig. 9 View Figs ), dorsally with 3-4 long black bristles, in addition a pair of preapical dorsal bristles. Hind tarsomere 1 as long as following four tarsomeres together; much widened; with a few long bristles near tip.

Wing ( Fig. 1 View Figs ) brownish clouded, stigma dark brown occupying the whole apex of cell R 1 (between tip of R 1 and R 2+3. The vein separating basal cells hardly prominent. Discal cell almost as long as basal cells, elongate rectangular (almost three times as long as wide). Apical portion of vein Cu, 1.5 times as long as vein closing the discal cell (dm-cu). Veins R 4+5 and M slightly diverging near middle, then converging and diverging again before meeting costa. Halter black. Squama and ciliation brown.

Abdomen shining black. Tergites dorsally with short pale brownish bristles; basal three tergites with very long pale bristles at sides. Sternites narrow, shining brownish black, with few moderately long dark hairs. Genitalia ( Fig. 13 View Fig ) with tip of right epandrial lamella bifurcate; outer lobe bearing flattened black bristly hairs, inner lobe with a row of ordinary hairs. Left epandrial lamella at tip also with flattened black bristly hairs. Cerci rather short. Tip of phallus very broad.

Female: length: 2.9–3.1mm; wing: 3 mm. In most respects identical to male.

Comments. – Syndyas singaporensis , new species superficially, resembles S. aterrima de Meijere from Ceram. The wing in the latter species is also brownish tinged, but veins R 4+5 and M are straight and run parallel toward costa. The hind femur bears a row of long ventral hairs and no spine-like bristles as in the new species.

S. singaporensis , new species, also resembles S. nigripes (Zetterstedt) that has however a slender hind femur with little dilated tip while the hind femur is more distinctly club-shaped in S. singaporensis , new species. The tip of the right surstylus is bifurcate in both species, but in S. singaporensis , new species, it bears flattened black bristly hairs while only ordinary hairs in S. nigripes . The shape of epandrial lamellae, length of cerci and shape of phallus are completely different in both species. Nevertheless we suppose that both species are closely related.