Macrostemum trifasciatum Banks, 1934

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 : 685-687

Macrostemum trifasciatum Banks, 1934

( Figs. 165–169 )

Macrostemum trifasciatum Banks, 1934: 575 [Holotype male; Malaysia; SMKM].

Diagnosis. Male. Antennae 33 mm in length. Antennal flagellum brown with darker striations. Forewing 15 mm and hindwing 10 mm in length. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Male genitalia. Inferior appendages two-segmented, harpago long and narrow ( Fig. 166 ). In lateral view, phallus apex flat without any protrusion ( Fig. 168 ), in dorsal view subrectangular ( Fig. 169 ). Segment IX in dorsal view subrectangular, without dorsal keel in posterior margin ( Fig. 167 ). Segment X in lateral view subtriangular with subbasal wart ( Fig. 166 ).

Female. Antennae 25 mm in length. Antennal flagellum brown with darker striations. Forewing 10 mm and hindwing 5 mm in length. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Material examined. Malaysia: 9 males, 9 females, Sabah, Kinabalu National Park , coll. I. Sivec, 22 April 1999 (HMPC) .

Distribution. Borneo.

Remarks. Original description by Banks (1934) did not include illustrations. Malicky (1998b) redescribed this species. This species can be easily distinguished from other congeners by the distinct wing pattern as shown in Fig. 165 .

Figures

Figs. 165–176. Macrostemum trifasciatum. 165, right forewing; Male genitalia: 166, lateral; 167, segment X dorsal; 168, phallus lateral; 169, phallus tip. Macrostemum zenon. 170, right forewing. Macrostemum sp. 171, right forewing; 172, right hind wing; Male genitalia: 173, lateral; 174, segment X dorsal; 175, phallus lateral; 176, phallus tip. Scale: 165, 170–172 = 2 mm; 166–169, 173–176 = 0.02 mm (170 redrawn from Malicky, O’Connor & Ashe, 2010).