Nemophora tristrigella (Walker, 1866)

Diagnosis of the tristrigella View in CoL species group and relationships among its species

The tristrigella species group ( Fig. 1 View FIGURE 1 ) can be diagnosed by the following combination of presumably apomorphic characters:

1. The vertex in males is medially covered with glossy golden scales.

2. The forewing fascia is narrow (0.03‒0.10 × FWL) and nearly straight.

3. The dark brown band of the forewing fascia extends continuously from the costa to the dorsum, while the yellow medial band is limited to the costal half of the wing.

4. The background forewing colour is light and glossy golden in the basal part of the forewing and darker, coppery bronze in the apical part of it.

5. A costal spot is present in the basal area of the forewing, usually matching its background colour; this spot is discernible only by a diffuse brown line bordering it dorsally.

6. The distal half of the forewing shows a characteristic pattern composed of several yellow spots surrounded by dark brown scales. This combination of pattern elements is unique to the tristrigella species group within Nemophora , although some features superficially resemble those seen in the kalshoveni species group from Indonesia and Papua New Guinea ( Kozlov 2016).

A tentative phylogeny of the tristrigella species group ( Fig. 1 View FIGURE 1 ) is proposed based on two presumably apomorphic characters:

7. The glossy golden coloration at the base of the forewing extends up to 0.4 × FWL.

8. Male compound eyes are enlarged, with an interocular index ranging from 1.15 to 1.75.

List of the species

Nemophora pendleburyi Kozlov , sp. nov.

Nemophora vitalii Kozlov , sp. nov.

Nemophora chalcotechna ( Meyrick, 1937)

Nemophora tristrigella ( Walker, 1866)

Key to the species by male external features

1. Compound eyes not enlarged: interocular index 0.5‒0.7....................................................... 2

-. Compound eyes enlarged: interocular index 1.15‒1.75........................................................ 3

2. Smaller: FWL 5.4 mm; glossy golden coloration of forewing base expands up to 0.17 × FWL; costal spot at forewing base extends to 0.25 × FWL...................................................................... N. pendleburyi

-. Larger: FWL 7.9‒9.2 mm; glossy golden coloration of forewing base expands up to 0.35 × FWL; costal spot at forewing base extends to 0.35 × FWL........................................................................... N. vitalii

3. Oblique yellow spot situated between 0.6 × costal margin and apex of forewing C-shaped; apical third of forewing usually with three additional yellow spots................................................................ N. chalcotechna

-. Oblique yellow spot situated between 0.6 × costal margin and apex of forewing S-shaped, sometimes split in two oval spots; apical third of forewing with one additional yellow spot............................................. N. tristrigella

Key to the species by male genitalia

1. Ventral margin of valva W-shaped; base of fused valvae medially with deep indentation (0.05‒0.07 × length of valva)............................................................................................... N. tristrigella

-. Ventral margin of valva nearly straight; base of fused valvae medially with minor indentation (0.01‒0.02 × length of valva).. ................................................................................................... 2

2. Internal surface of valva with a distinct medial lobe.................................................... N. vitalii

-. Internal surface of valva without a distinct lobe............................................................. 3

3. Medial process of transtilla short (less than 2 × phallus diameter); tips of valvae extend beyond tip of tegumen; valvae fused basally to each other and to vinculum; internal valvar margins indistinct; length of vinculum 2.0‒2.1 × length of valva............................................................................................. N. chalcotechna

-. Medial process of transtilla long (more than 2 × phallus diameter); tips of valvae at about same level as tip of tegumen; valvae fused basally to each other but not to vinculum; internal valvar margins distinct; length of vinculum 2.4 × length of valva........................................................................................... N. pendleburyi