Macrostemum tonkinensis Mosely, 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

Macrostemum tonkinensis Mosely, 1934

( Figs. 160–164 )

Macrostemum tonkinensis Mosely, 1934: 140 [Holotype male; Vietnam; BMNH].

Diagnosis. Male. Antennae about 35 mm long. Antennal flagellum dark brown in first few segments, and lighter throughout. Forewing 12 mm and hind wing length 10 mm. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Male genitalia. Inferior appendages two-segmented, harpago broad. Phallus when viewed laterally has circular apex with very obvious opening in the middle ( Fig. 163 ), when viewed dorsally has a curved apex ( Fig. 164 ).

Female. Antennae about 20 mm long. Antennal flagellum dark brown in first few segments, and lighter throughout. Forewing 13 mm and hind wing length 8 mm. Mesoscutum and mesoscutellum without evident markings. Tibial spurs 2.4.4.

Material examined. Vietnam: 13 males, 21 females, Tam Dao, coll. H. Malicky, 19 May–13 June 1995 (HMPC) ; Laos: 1 female, Hua Phan Province, Phou Pan, coll. C. Holzschuh, 1–10 May 2011 (HMPC) .

Distribution. Vietnam, Laos.

Remarks. The forewing pattern was consistent among the examined specimens; a white C-shaped marking occupied almost half of the forewing from the anterior area ( Fig. 160 ). Male genitalia were redrawn ( Figs. 161–164 ).

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.