Black Riverdarter

Scientific name:  Onychothemis tonkinensis

Habitat: fast-flowing streams

Body length: 54-58 mm

Distribution in Hong Kong: Mainly in north New Territories, e.g. Tan Shan River, Ping Shan Chai

Flight period in Hong Kong: July to October

Identification features: 

1. Eyes green

2. Synthorax and abdomen black, with yellow stripes

3. Broad vertical yellow stripes on dorsal carina

4. Oval yellow spots at two sides of the 3rd to 7th abdominal segments