Macrostemum punctatum Betten, 1909

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 : 683

Macrostemum punctatum Betten, 1909

( Figs. 142–148 )

Macrostemum punctatum Betten, 1909: 232 [Holotype male; India; NZSI].

Macrostemum mithras Malicky & Chantaramongkol, 2003: 917 [Holotype male; Thailand; HMPC; synonymised by Malicky, 2013: 47].

Diagnosis. Male. Antennae 40 mm in length. Antennal flagellum first few segments darker brown then lighter throughout with darker striations. Forewing 13 mm and hind wing 7 mm in length. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Male genitalia. Inferior appendages two-segmented ( Fig. 145 ). In lateral view, phallus apex circular, with longer posterior area ( Fig. 147 ). In ventral view, phallus with lobular tongue at apex ( Fig. 148 ). In lateral view, segment X broad and narrowing through apex ( Fig. 145 ) and divided at middle with wide separation in dorsal view ( Fig. 146 ).

Female. Antennae broken. Antennal flagellum first few segments darker brown then lighter throughout with darker striations. Forewing 13 mm and hind wing 7 mm in length. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Type material examined. Holotype. Thailand: male, Khampaeng Phet Province , Klong Lan National Park, coll. CMU, 7 March 2002 (HMPC).

Paratypes. Thailand: 7 males, Khampaeng Phet Province , Klong Lan National Park, coll. CMU, 7 March 2002 (HMPC) .

Additional material examined. Nepal: 4 males, 5 females, Harare Province , coll. Jiri, Allen, 25 May 1991 (HMPC) ; 10 males, 2 females, Mahadev Khola, coll. H. Malicky, 12–13 April 1995 (HMPC); 20 males, 5 females, Ganesh, Himal, coll. G. Karki, 15 May 1999 (HMPC).

Distribution. India, Nepal, Thailand.

Remarks. Three types of wing patterns were observed ( Fig. 142–144 ). The species was initially described as possessing two thick rectangular dark-brown spots running across the width of its forewing ( Fig. 143 ). However, some specimens lacked wing markings ( Fig. 142 ). The three types of wing patterns were even observed among the specimens from same locality.

Figures

Figs. 142–148. Macrostemum punctatum. 142–144, right forewing variants; Male genitalia: 145, lateral; 146, segment X dorsal; 147, phallus lateral; 148, phallus tip. Scale: 142 = 2 mm; 145–148 = 0.02 mm.