Male body length 17-22 mm, the largest firefly in Hong Kong; windows at the posterior part of the pronotum distinct, lunate; light organs transverse, located at 6th and 7th ventrite. Female body length 32-47 mm, bearing a pair of short and small elytra, shape varies, light organs rounded, one pair at 6th abdominal ventrite, another pair at 7th. Larva black, body length of the largest record 65mm; irregularly scattered with small light brown spots, a pair of light organs located at 8th abdominal segment. Lateral sides of the last 2 tergites almost straight, different from the rounded lateral sides of the last 2 tergites in Pyrocoelia analis.
：More than 10 locations of lowland and highland natural woodlands as well as highland grasslands have records
Adult flight period
Late October to early December
flies slowly, showing continuous glow, appears late, about 1 hour after sunset, keeps active for about 3 more hours. Female is very rarely recorded. Larva feeds on snails. Endemic to Hong Kong.