Nemophora tristrigella ( Walker, 1866 )

Kozlov, Mikhail V., 2025, A taxonomic revision of the tristrigella species group of the genus Nemophora Hoffmannsegg (Lepidoptera, Adelidae) from the Philippines, Malaysia, Brunei and Indonesia, Zootaxa 5665 (1), pp. 99-110 : 106-108

Nemophora tristrigella ( Walker, 1866)

( Figs. 7‒9 , 13 , 17 , 20 )

Nemotois tristrigella : Walker 1866: 1815. Holotype ♂: Indonesia, Java; labelled: 8 mm circle with red border, print ‘ Holo- │ type’; 8 mm circle with red border, print ‘ Type’; 5 × 6 mm, print ‘60-15 │ E.I.C. [East India Company]’; 8 × 5 mm, black ink ‘773.’; 14 × 25 mm, black ink + print ‘ Nemotois │ tristigella Wkr. │ Cat Lep BM. 35, 1815 (1866) │ TYPE ♂ 1/1’;

4 × 32 mm, print ‘ Nemotois tristrigella .’; 8 × 20 mm, print ‘ HOLOTYPE ♂ │ Nemotois tristrigella │ Walker, 1866 │ M. Kozlov design. 1999’ (NHM) [examined].

Nemotois tristrigella : Meyrick 1912a: 7, 1912b: 8.

Nemophora tristrigella : Diakonoff 1951: 158‒160, fig. 13 (male genitalia).

Other material. Indonesia. 5 ♂ 3 ♀, Sumatra, Marang , vii.–ix.1890 (Doherty) ( NHM) ; 1 ♂, Sumatra, Padang , 3.ix.1913 (Jacobson) ( RMNH) ; 1 ♂, Sipura Island , 9.x.1924 (Karny) ( NHM) ; 1 ♂, Java, Kalipari , 1891 (Doherty) ( NHM) ; 1 ♂, Java, Preanger, Mount Djampang , 1500‒2500 ft., ii.–iii.1936 (Walsh) ( NHM) ; 1 ♂, Java, Buitenzorg, Depok , 7.iii.1941 (Toxopeus) ( RMNH) ; 1 ♂, Java, Buitenzorg, 1894 ( RMNH) ; 1 ♂, Java, Cibodas , 22.ix.1929 (Lieftinck) ( RMNH) ; 1 ♂, Java, Depok, 1886 ( RMNH) ; 1 ♀, ibid., 1885 ( RMNH) ; 1 ♀, ibid., 1883 ( USNM) ; 1 ♂, Java, Jakarta, 1886 ( RMNH) ; 18 ♂ 2 ♀, Bali, 1896 (Doherty) ( NHM) ; 1 ♂, Borneo, Balikpapan, Wain River , xi.1950 (Wegner) ( RMNH) ; 1 ♂, Borneo, Gunungsari , 21.viii.1956 (Wegner) ( RMNH) ; 1 ♂, Kangean Archipelago, Petapan , 20.ix.1954 (Hoogerwerf) ( RMNH) . Philippines. 1 ♂, Tawi-Tawi Island , 22.xi.1961 (Noona Dan Expedition) ( ZMUC) .

Diagnosis. Nemophora tristrigella is closely related to N. chalcotechna ( Figs. 4‒6 ), from which differs by the shallowly S-shaped, oblique yellow spot positioned between 0.56‒0.62 × FWL at the costal margin and the apex of the forewing, which is sometimes split in two separate spots; a shorter distance (0.09‒0.10 × FWL) between the external margin of the fascia’s yellow band and the internal margin of this spot; longer male antenna (3.9‒4.1 × FWL) and a larger arrow head of juxta (exceeding half of the juxta’s total length).

Description. Male ( Figs. 7, 8 ). FWL 6.2‒7.7 mm, WLR 0.36‒0.40. Vertex glossy golden medially, bordered anteriorly and posteriorly by dark brown piliform scales. Frons glossy golden, bearing a few brown piliform scales below antennal sockets. PLB 0.6 × vertical eye diameter (1.05‒1.15 × length of scape), covered by light yellowish brown appressed scales. Proboscis light brown. Eyes enlarged, but not touching each other; interocular index 1.4‒ 1.6, occipital distance 0.15‒0.30. Antenna 3.9‒4.1 × FWL. Scape shining coppery bronze; 8‒12 basal flagellomeres dark brown, first 3‒5 of them thickened by raised dark coppery brown scales; distal part of flagellum silver grey. Tegulae and thorax golden. Forewing basally (up to 0.4 × FWL) glossy golden; costal spot at forewing base extends to 0.35 × FWL ( Fig. 13 ). Fascia dark brown, straight, narrow (0.07 × FWL at costa, 0.05 × FWL at dorsum), slightly oblique; inner margin of fascia reaches costa at 0.39‒0.47 × FWL; costal half of fascia with yellow medial band. Distal part of forewing bronze with coppery iridescence, with two or three yellow spots surrounded by dark brown scales; long axes of these spots parallel to each other. Two of these spots, one touching costa at 0.56‒0.62 × FWL and another at wing apex, are connected by narrow band of dark brown scales sometimes including yellow line, forming S-shaped figure. Third yellow spot near termen clearly isolated from two other spots. Fringe gold to bronze apically to brown with coppery iridescence basally. Hindwing brown, with slight coppery iridescence; costal area grey; fringe brown. Legs golden proximally to dark coppery brown distally; bases of all tarsomeres pale yellow. Epiphysis at 0.5, reaching (or almost reaching) apex of tibia. Abdomen light brown.

Female ( Fig. 9 ). FWL 6.0‒ 6.3 mm, wider than in male: WLR 0.42‒0.46. Antenna 1.5‒1.8 × FWL; base not thickened. Abdomen brown dorsally, gold to coppery ventrally. Otherwise similar to male.

Male genitalia ( Figs. 17 , 20 ). Tegumen wide, dome-shaped, with distinct medial ridge. Socii 1.3 × diameter of phallus. Vinculum 1.8‒2.2 × length of valva, with slightly convex lateral margins and shallowly W-shaped distal margin. Tips of valvae extend beyond tip of tegumen. Ventral margin of valva medially with prominent lobe; dorsal margin with slight protrusion in the middle; tip of valva narrowly rounded. Valvae fused basally up to 0.4 × total length; their internal margins indistinct; base of fused valvae medially with deep, narrow indentation (0.05‒0.07 × length of valva). Anellus 0.4 × length of valva. Transtilla with short triangular medial process. Juxta 0.6 × length of phallus; arrow head wide (WLR 0.6), with pointed tip and pointed lateral arms; it exceeds half of juxta’s total length. Phallus 1.0‒1.1 × length of vinculum, in lateral view shallowly S-shaped. Tip of phallus slightly wider than its medial part, with deep ventral incision and small dorsal indentation; base of phallus narrowly funnel-shaped.

Distribution. Indonesia (Sumatra, Sipora, Java, Bali, Borneo, Kangean), Philippines (Tawa-Tawa).

Comments. Although A. Diakonoff misidentified one specimen of N. chalcotechna from Mindanao (housed in NHM) as N. tristrigella , his description of N. tristrigella ( Diakonoff 1951) is accurate.

Figures

FIGURES 2–9. Adults of Nemophora spp. 2, N. pendleburyi Kozlov, sp. nov., male, holotype, from Selangor, Malaysia; 3, N. vitalii Kozlov, sp. nov., male, holotype, from Brunei; 4, N. chalcotechna (Meyrick, 1937), male, holotype, from Mindanao, the Philippines; 5, ditto, male, from Basilan Island, the Philippines; 6, ditto, female, from the same locality; 7, N. tristrigella (Walker, 1866), male, holotype, from Java, Indonesia; 8, ditto, male, from Balikpapan, Indonesia; 9, ditto, female, from Indonesia. Scale bar: 2 mm.

FIGURES 10–13. Forewing pattern of Nemophora spp. 10, N. pendleburyi Kozlov, sp. nov.; 11, N. vitalii Kozlov, sp. nov.; 12, N. chalcotechna (Meyrick, 1937); 13, N. tristrigella (Walker, 1866). Scale bar: 2 mm.

FIGURES 14–17. Male genitalia of Nemophora spp. 14, N. pendleburyi Kozlov, sp. nov.; 15, N. vitalii Kozlov, sp. nov.; 16, N. chalcotechna (Meyrick, 1937); 17, N. tristrigella (Walker, 1866); a: genital complex, ventral view (right valva not shown); b: genital complex, lateral view; c: juxta; d: phallus, ventral view; e: phallus, lateral view. Scale bar: 0.2 mm.

FIGURES 18–20. Male genitalia of Nemophora spp. 18, N. vitalii Kozlov, sp. nov., holotype, from Brunei, genitalia preparation 29464 (NHM); 19, N. chalcotechna (Meyrick, 1937), from Basilan Island, the Philippines, genitalia preparation 29977 (NHM); 20, N. tristrigella (Walker, 1866), from Marang, Indonesia, genitalia preparation 29973 (NHM); a: genital complex, ventral view; b: phallus; c: apex of phallus; d: juxta. Scale bar: 0.2 mm (valid for a, b and d only).