Macrostemum fastosum Walker, 1852

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 : 677

Macrostemum fastosum Walker, 1852

( Figs. 90–94 )

Macrostemum fastosum Walker, 1852: 76 [Holotype male; Hong Kong; BMNH]; Malicky, 1998b: 769 (redescription).

Macronema tripunctatum Banks, 1924: 451 [Holotype male; Philippines; MCZ; synonymised by Fischer, 1963: 186].

Diagnosis. Male. Antennae 35 mm in length. Antennal flagellum brown; darker colour of striations not obvious. Forewing 14 mm and hind wing 7 mm in length with dark brown stripe along middle of forewing; apex with evident dark brown markings ( Fig. 90 ). Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Male genitalia. Inferior appendages two-segmented, harpago long. In lateral view, phallus with longer posterior area of apex ( Fig. 93 ). In dorsal view, segment X divided at middle and pointed toward apex laterally ( Fig. 92 ).

Female. Antennae 30 mm in length. Antennal flagellum dark brown in first few segments, and lighter throughout. Forewing 14 mm and hind wing 9 mm in length, same pattern as male. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Material examined. Thailand: 20 males, 15 females, Mae Kampong, Mae La stream, coll. C.J. Uy, 14 May 2015 ( UPLBMNH) ; Vietnam: 7 males, 13 females, Tam Dao , coll. H. Malicky, 19 May–13 June 1995 (HMPC) ; Indonesia: 7 males, 13 females, Sumatra, Simarito , coll. H. Malicky, 14 February 1994 (HMPC) ; Laos: 1 female, Luang Prabang Province, coll. C. Holzschuh, 24 April–16 May 1999 (HMPC).

Distribution. Burma, China, India, Java, Bali, Laos, Malaysia (Perak), Nepal, Philippines, Thailand, Vietnam.

Remarks. This species can be easily distinguished from other congeners from its distinct wing pattern ( Fig. 90 ). However, we observed that specimens from Vietnam have thicker brown stripes on forewings. Other diagnostic characters are illustrated in Figs. 91–94 .

Figures

Figs. 85–94. Macrostemum eleanora. 85, right forewing; Male genitalia: 86, lateral; 87, segment X dorsal; 88, phallus lateral; 89, phallus tip. Macrostemum fastosum. 90, right fore- and hind wing; Male genitalia: 91, lateral; 92, segment X dorsal; 93, phallus lateral; 94, phallus tip. Scale: 85, 90 = 2 mm; 86–89, 91–94 = 0.02 mm.