Firefly survey at the Mai Po Nature Reserve

During the past few months WWF has carried out surveys of the Mai Po Bent-winged Firefly Pteroptyx maipo, a species unique to Deep Bay. The survey aimed to understand the seasonal population changes, distribution and habitat requirements of the species around Mai Po Nature Reserve (MPNR).

The Mai Po Bent-winged Firefly was first discovered by local entomologists in 2010 summer in Deep Bay. Not only is the species new to science, but it was also the first time for the genus Pteroptyx to be recorded in China. Most firefly species of the Pteroptyx genus are found in mangrove area in South-east Asia, where hundreds of adult fireflies congregate on top of mangrove trees during summer nights. The Mai Po Bent-winged Firefly does not congregate in the same way, but can still provide spectacular scenery at night.

According to the survey carried out by WWF researchers from April to October 2012, the Mai Po population peaks in May (when almost 400 individuals were seen in a single night) and September (when almost 700 individuals could be seen). These were found mostly in intertidal areas, especially near the southern MPNR, rather than in the gei wai. Among the known sites in Deep Bay where the species can be found, the MPNR supports the highest reported population and is therefore vital for the long-term survival of the species.