Hercostomus meieri, Zhang & Yang & Grootaert, 2008

Zhang, Lili, Yang, Ding & Grootaert, Patrick, 2008, Mangrove Hercostomus Sensu Lato (Diptera: Dolichopodidae) Of Singapore, Raffles Bulletin of Zoology 56 (1), pp. 17-28 : 25-27

Hercostomus meieri , new species

( Figs. 25–28 )

Material examined. – Holotype. Male , SINGAPORE: Pulau Ubin, Chek Jawa, 2 Dec.2003, mangrove (23097, coll. PG, det. LZ, Si113, ZRC).

Paratypes. Pulau Ubin, Chek Jawa, 4 males, 3 females, 11 Dec.2002 (sweeping); 5 males, 1 female, 2 Dec.2003 (3 males and 1 female kept in IOZ) ; 5 males, 11 Dec.2003; 4 males, 5 females, 22 Dec.2005; 4 males, 1 female, 30 Dec.2005. Sungei Buloh, 1 female, 25 May 2005; 3 females, Sungei Buloh, 6 Jul.2005; 1 female, 3 Dec.2005.

Diagnosis. – First flagellomere 3.0 times as long as wide. Fore coxa yellow, mid and hind coxae brown.

Description. – Male. Body length 2.4–2.5 mm, wing length 2.1–2.2 mm.

Head metallic green with pale grey pollen. Face narrowing downward, slightly narrower than first flagellomere. Hairs and bristles black. Postocular bristles (including posteroventral hairs) black. Antenna ( Fig. 25 ) brown, first flagellomere 3.0 times as long as wide; arista black, apicodorsal, minutely pubesecent with short basal segment. Proboscis blackish brown with black hairs, palpus blackish brown with black hairs and black apical bristles.

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 brown. Mid tarsus from tip of tarsomere 1 onward brownish; hind tarsus 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, 1 weak pd and 1 pv, 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 av, 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 1.35: 0.6: 0.35: 0.25: 0.17: 0.17; LIII 1.5: 0.5: 0.65: 0.45: 0.3: 0.25. Wing hyaline, tinged with grey, veins brown; CuAx ratio 1.0. Squama yellow with black hairs. Halter yellow.

Abdomen metallic green with pale grey pollen. Hairs and bristles black. Male genitalia ( Figs. 26–28 ): Epandrium longer than wide, lateral epandrial lobe slightly swollen apically with 3 bristles; cercus nearly triangular; hypandrium short and obtuse apically; aedeagus with 1 inner denticle.

THE RAFFLES BULLETIN OF ZOOLOGY 2008

Female. Body length 2.4 mm, wing length 2.4 mm. Similar to male, but first flagellomere shorter, 1.7 times as long as wide.

Etymology. – The species is dedicated to Dr. Rudolf Meier from National University of Singapore.

Distribution. – Singapore.

Remarks. – The new species is distinguished from other known species by the long first flagellomere that is three times as long as wide.

Figures

Figs. 25–28. Hercostomus meieri, new species, male: 25, antenna; 26, male genitalia; 27, hypandrium and aedeagus, ventral view; 28, cercus.