Macrostemum floridum Navás, 1929

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 : 677-679

Macrostemum floridum Navás, 1929

( Figs. 107–111 )

Macrostemum floridum Navás, 1929: 41 [Holotype male; China; MNHN]; Malicky, 1998b: 777 (redescription); Hoang et al., 2005: 167 (female description).

Diagnosis. Male. Antennae 25 mm in length. Antennal flagellum dark brown in first few segments, lighter throughout. Forewing 10 mm and hindwing 7 mm in length. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Male genitalia. Inferior appendages two-segmented, harpago long ( Fig. 108 ). In lateral view, phallus with pointed structure originating from posterior pointing apically but very minute not like other species ( Fig. 110 ). In dorsal view, phallus with lobular tongue in apex ( Fig. 111 ). In lateral view, segment X broad tapering to apex, directed dorsad in some specimens ( Fig. 108 ), each lobes widely separated in dorsal view ( Fig. 109 ).

Female. Antennae broken. Antennal flagellum dark brown in first few segments, and lighter throughout. Forewing 11 mm and hindwing 9 mm in length. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Material examined. Thailand: 1 male, Chiang Mai, Chiang Mai Zoo, coll. P. Chantaramongkol & H. Malicky, 28 August–4 September 1989 (HMPC); Vietnam: 5 males, 16 females, Nam Cat Tien, coll. H. Malicky, 17–25 June 1995 (HMPC) ; India: 1 male, Kerala , Kallar, coll. Dembicky & Pacholatko, 1–9 May 1997 (HMPC); Laos: 3 males, 2 females, Luang Prabang Province , Khan River , coll. C. Holzschuh, 21 April 1999 (HMPC) ; 2 females, Attapeu Province , Annam Highlands Mountains , coll. J. Hajek, 30 April–6 May 2010 (HMPC) .

Distribution. China, India, Cambodia, Laos, Thailand, Vietnam.

Remarks. The original description of this species in Navás (1917) (in Latin) provided only forewing illustration lacking male genitalia illustration. Malicky (1998b) redescribed the male of this species. The wing colour pattern ( Fig. 107 ) and the phallus structure in lateral view ( Fig. 110 ) are consistent among the specimens examined in this study. Segment X has variations in the described species. Some specimens described from Vietnam have pointed apex of segment X in lateral view ( Fig. 108 ) while broad in specimens from other area. We provide redescription of this species based on our recent materials.

Figures

Figs. 95–111. Macrostemum fenestratum. 95–101, right forewing variants; Male genitalia: 102, lateral; 103–104, segment X variants dorsal; 105, phallus lateral; 106, phallus tip. Macrostemum floridum. 107, right forewing; Male genitalia: 108, lateral; 109, segment X dorsal; 110, phallus lateral; 111, phallus tip. Scale: 95–101, 107 = 2 mm; 102–106, 108–111 = 0.02 mm.