Mangrove Hercostomus Sensu Lato (Diptera: Dolichopodidae) Of Singapore Author Zhang, Lili Author Yang, Ding Author Grootaert, Patrick text Raffles Bulletin of Zoology 2008 2008-02-29 56 1 17 28 journal article 10.5281/zenodo.5339229 2345-7600 5339229 Hercostomus plumatus , new species ( Figs. 29–32 ) Material examined. – Holotype . Male , SINGAPORE : Sungei Buloh , 11 May 2005 , Mal. 1 (25159, coll. PG, det. LZ, Si812, ZRC ). Paratypes . SINGAPORE : Pulau Ubin , Chek Jawa , 2 females , 30 Dec.2005 ; 4 females , 30 Dec.2005 (sweeping). Sungei Buloh, 1 male , 27 Nov.2003 (sweeping); 3 males , 1 female , 22 Apr.2005 ; 5 males , 27 Apr.2005 ; 4 males , 5 females , 11 May 2005 ( 3 males and 2 females in IOZ ) ; 11 males , 11 May 2005 ; 2 males , 18 May 2005 ; 4 males , 25 May 2005 ; 1 female , 1 Jun.2005 ; 1 male , 10 June 2005 ; 1 male , 15 Jun.2005 ; 1 male , 5 Aug.2005 ; 1 male , 26 Aug.2005 ; 1 male , 1 female , 18 Nov.2005 ; 1 female , 3 Dec.2005 ; 1 male , 4 Jan.2006 . Diagnosis . – First flagellomere 1.2 times as long as wide. Fore coxa yellow, mid and hind coxae brownish. Dorsal lobe of surstyli with plumose hair. Description . – Male . Body length 2.4–2.7 mm , wing length 2.2–2.5 mm . Head metallic green with pale grey pollen. Face narrowing downward, narrower than first flagellomere. Hairs and bristles black. Postocular bristles (including posteroventral hairs) black. Antenna ( Fig. 29 ) brownish; first flagellomere darker, 1.2 times as long as wide; arista dark brown, minutely pubescent with short basal segment. Proboscis brownish yellow with black hairs, palpus brownish yellow with black hairs and black apical bristle. Figs. 29–32. Hercostomus plumatus , new species , male: 29, antenna; 30, male genitalia; 31, cercus; 32, surstyli. Thorax metallic green with pale grey pollen. Six strong dc, 5–6 pairs of acr; scutellum with two pairs of bristles (basal pair short and weak). Propleuron with 1 black bristle on lower part. Legs yellow; fore coxa yellow, mid and hind coxae brownish. Mid and hind tarsi from tip of tarsomere 1 onward brownish to brown. Hairs and bristles black. Mid and hind coxae each with 1 exterior bristle. Mid and hind femora each with 1 preapical bristle. Fore tibia with 2 ad and 1 weak pd, apically with 3 bristles; mid tibia with 3 ad, 2 pd and 1 av, apically with 4 bristles; hind tibia with 4 ad, 3 pd and 2 vs., apically with 3 bristles. Relative lengths of tibia and 5 tarsomeres LI 1.0: 0.5: 0.2: 0.15: 0.15: 0.15; LII 1.5: 0.65: 0.4: 0.3: 0.2: 0.2; LIII 1.65: 0.5: 0.7: 0.5: 0.35: 0.25. Wing hyaline, tinged with greyish, veins brown; CuAx ratio 0.9, R 4+5 and M parallel apically. Squama yellow with black hairs. Halter yellow. Abdomen metallic green with pale grey pollen. Hairs and bristles black. Male genitalia ( Figs. 30–32 ): Epandrium longer than wide, lateral epandrial lobe slightly curved apically with 3 bristles; cercus nearly triangular; hypandrium narrow and straight; aedeagus with 1 minute, inner denticle. Female. Body length 3.3 mm , wing length 2.9 mm . Similar to male, but fore tibia without weak pd. Etymology . – The specific name refers to the plumose hair on the dorsal lobe of surstyli. Distribution . – Singapore . Remarks . – The new species is somewhat similar to H. brevicornis , new species , but may be separated from the latter by its triangular cercus and aedeagus with 1 inner denticle; in H. brevicornis , new species , the cercus is strongly curved and nearly geniculate and the aedeagus has 2 inner denticles.