I first met a person formerly from Tioman in Rompin, on the February 2010. He mentioned that there are congregating fireflies in Tioman at the mangrove rivers. Since it was too expensive to go there, probably there will be a chance in the future. The chance came in April 2013, when I did my first recce under the Malaysian Nature Society’s Revisiting Our Original TreeS (ROOTS) project in Tioman. The villagers mentioned that the Juara-Tekek road are ”abundant’ but not so much along the small tidal mangrove rivers.
22 July 2013:
The first night survey trip to Tioman Island. We canoed along one navigable mangrove river in Kg Juara on a full moon day. Only a few roving fireflies flying and glowing along the bank. Possibly the abundance of the congregating fireflies is not great, therefore it became a seasonal event. According to the villagers, there are on at certain times, but they mentioned that at 8 pm along the roadside the fireflies are more.
We spotted a tiny black spiny larvae (10-11mm) belonging to the Luciolinae sub-family, an unknown tiny blinking flightless female (5-6mm), a dark Pyrocoelia larva (25mm) and a glowing dark orange headed Pyrocoelia male (10-11mm) along the road side and waterfall area.
25 July 2013: Returned to the spot further up the road. A glowing Diapahnes male (9-10mm) and a larva (15mm) near to each other; a Luciolinae male firefly (5-6mm) with dark wing tips and the half moon light organ that glows weakly, possibly a Curtos firefly with evenly spaced dimples on the wing shield and with a prominent ridge; and a dark male Luciolinae firefly (3-5mm), with two huge eyes, bigger than the width of its slender body with an orange pronotum and a half moon light organ which blinks regularly. It has evenly spaced dimples on the wing shields and a prominent ridge which is possibly a Curtos too.
Malaysian Firefly Blog 