Scientific name: Labrogomphus torvus

Habitat: open stream

Body length: 77-83 mm

Distribution in Hong Kong: Mainly in north and central New Territories, e.g. Hok Tau, Tan Shan river, Sham Tseng

Flight period in Hong Kong: April to September

Identification features: 

1. A large yellow spot on the 7th abdominal segment

2. Length of the 9th abdominal segment more than double of the 8th