A key to species of Leucoma Hübner in China

1 Forewings yellow brown......................................................................... L. sartus

- Forewings white or silvery white......................................................................... 2

2 Thorax with two dark dots or oblique lines................................................................. 3

- Thorax without dark dots or slashes....................................................................... 4

3 Hind tarsi white............................................................................... L. sericea

- Hind tarsi black............................................................................ L. melanoscela

4 Legs white, with black circles on tarsi..................................................................... 5 - Legs white, without black circles on tarsi.................................................................. 6

5 Main stem of antennae white, with black-brown stripes................................................ L. candida

- Main stem of antennae white, without black-brown stripes............................................... L. salicis

6 Forewings with a black edge at the basal area of costa................................................. L. costalis

- Forewings without black edges at the basal area of costa...................................................... 7

7 Frons with a black spot.......................................................................... L. niveata

- Frons without black spots............................................................................... 8

8 Forewings with silvery white bands....................................................................... 9

- Forewings without silvery white bands................................................................... 12

9 Forewing with three arcuate white oblique bands....................................................... L. clara

- Forewings with two or three parallel oblique bands......................................................... 10

10 Pectionations of antennae pale tawny.............................................................. L. impressa

- Pectionations of antennae dark brown.................................................................... 11

11 Vesica of aedeagus with four sclerotized digitate projections........................................... L. parallela

- Vesica of aedeagus without sclerotized digitate projections.......................................... L. chrysoscela

12 Left valva longer than right valva..................................................... L. nyingchiensis sp. nov.

- Left valva shorter than right valva....................................................................... 13

13 Labial palpi orange yellow...................................................................... L. ochripes

- Labial palpi white...................................................................... L. sichuana sp. nov.