Macrostemum seba Malicky & Prommi, 2009

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

Macrostemum seba Malicky & Prommi, 2009

( Figs. 154–159 )

Macrostemum seba Malicky & Prommi (in Malicky, 2009): 47 [Holotype male; Thailand; HMPC.]

Diagnosis. Male. Antennae 20 mm in length. Antennal flagellum first few segments darker brown then lighter throughout with darker striations. Forewing 10 mm and hind wing 6 mm in length. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Male genitalia. Inferior appendages two-segmented, harpago blunt towards the apex ( Fig. 156 ). In lateral view, phallus with spine-like structure at anterior portion of apex ( Fig. 158 ). In dorsal view, phallus with lobular tongue in anterior part of apex ( Fig. 159 ). In lateral view, segment X with broad apex ( Fig. 156 ), forming U-shape at middle of two lobes in dorsal view ( Fig. 157 ).

Type material examined. Holotype. Thailand: male, Phangnga Province, Sriphanga National Park , coll. T. Prommi, 7 August 2004 (HMPC).

Paratypes. Thailand: 4 males, Phangnga Province, Sriphanga National Park , coll. T. Prommi, 7 August 2004 (HMPC) ; 6 males, Ranong Province, Klongbangmun stream, coll. T. Prommi, 8 October 20014 (HMPC) .

Additional material examined. Laos: 1 male, Boli, Kham Xai Province , coll. V. Kuban, 1–18 May 2001 (HMPC) .

Distribution. Thailand, Laos.

Remarks. The phallus resembles that of M. dione dorsally. However, the phallus of M. seba possesses both dorsal and ventral tongues, whereas that of M. dione has only one ( Fig. 159 ). The original description of the species included drawings of two types of genitalia and wing patterns. The genitalia drawings included here are based on both the holotype and paratype specimens, and both wing pattern variations were drawn as well ( Figs. 154–159 ). No female specimens were available for examination.

Figures

Figs. 149–164. Macrostemum quinquepunctatum. 149, right forewing; Male genitalia: 150, lateral; 151, segment X dorsal; 152, phallus lateral; 153, phallus tip. Macrostemum seba. 154–155, right forewing; Male genitalia: 156, lateral; 157, segment X dorsal; 158, phallus lateral; 159, phallus tip. Macrostemum tonkinensis. 160, right forewing; Male genitalia: 161, lateral; 162, segment X dorsal; 163, phallus lateral; 164, phallus tip. Scale: 149, 154–155, 160 = 2 mm; 150–153, 156–159, 161–164 = 0.02 mm.