Macrostemum distinguendum Ulmer, 1905

Uy, Christine Jewel C., Malicky, Hans & Bae, Yeon Jae, 2018, Review of the filter-feeding caddisfly subfamily Macronematinae (Trichoptera: Hydropsychidae) in tropical Southeast Asia, Raffles Bulletin of Zoology 66, pp. 664-703 : 674

Macrostemum distinguendum Ulmer, 1905

( Figs. 75–79 )

Macrostemum distinguendum Ulmer, 1905b: 71 [Holotype male; Sumatra; SM].

Diagnosis. Male. Antennae 25 mm in length. Antennal flagellum first few segments darker brown then lighter throughout with darker striations. Forewing 10 mm and hindwing 5 mm in length with three V-shape white markings and one small white elongated pattern runs parallel to the wing length ( Fig. 75 ). Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Male genitalia. Inferior appendages two-segmented ( Fig. 76 ). Phallus when viewed laterally has pointed structure in apex directed apically ( Fig. 78 ). In dorsal view, phallus has protrusion like apical tongue ( Fig. 79 ). In dorsal view, segment X divided medially throughout the center ( Fig. 77 ).

Female. Antennae 25 mm in length. Antennal flagellum same colouration as male. Forewing 12 mm and hindwing 7 mm in length. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Material examined. Indonesia: 1 male , Sumatra, Padang , coll. E.W. Diehl, 24 October 1990 (HMPC) ; 2 females, Sumatra, Kebun Sei Kopas , coll. H. Malicky, 29 April 1997 (HMPC) ; Malaysia: 4 males, 2 females , Hulu , Perak, coll. I. Sivec, 1–3 April 1994 (HMPC) ; 1 female, Sarawak, Bako National Park , coll. I. Sivec, 10 May 1999 (HMPC) .

Distribution. Borneo, Sumatra.

Figures

Figs. 70–84. Macrostemum dione. 70, right forewing; Male genitalia: 71, lateral; 72, segment X dorsal; 73, phallus lateral; 74, phallus tip. Macrostemum distinguendum. 75, right fore- and hind wing; Male genitalia: 76, lateral; 77, segment X dorsal; 78, phallus lateral; 79, phallus tip. Macrostemum dohrni. 80, right forewing; Male genitalia: 81, lateral; 82, segment X dorsal; 83, phallus lateral; 84, phallus tip. Scale: 70, 75, 80 = 2 mm; 71–74, 76–79, 81–84 = 0.02 mm.