Scientific name: Potamarcha congener

Habitat: marsh, pond

Body length: 43-45 mm

Distribution in Hong Kong: Mainly in north New Territories and Lantau Island, e.g. Tan Shan River, Sha Lo Tung

Flight period in Hong Kong: February to October

Similar species: Indigo Dropwing (Comparison: male)

Identification features (male): 

1. Synthorax pruinose grey blue

2. Vertical yellow spots on dorsum and two sides of the abdomen

Identification features (female): 

1. Synthorax and abdomen mainly yellowish brown

2. Three black vertical stripes on dorsum of abdomen; the central stripe thinner