FOR the longest time, we’ve been told that to save the fireflies we have to save the sonneratia caseolaris, or better known as berembang trees.
It makes sense, as these are the trees that fireflies flock to at night and flash their brightest, giving berembang-rich areas like Kuala Selangor the kind of glow that draws in top tourist dollar every year.But local scientists have revealed that conserving the berembang alone isn’t going to be enough.
Fireflies socialise on the trees, but it is on the ground that female fireflies lay their eggs and the larvae grow to become adults. A firefly may spend up to 80 per cent of its lifespan on the ground.
For this reason, conserving the stretch of land by the riverbank and its natural vegetation is just as important for the survival of fireflies.
In some areas in Kuala Selangor, private landowners tend to develop their land right up to the riverbank, leaving just a thin strip of berembang standing.
“The berembang tree is not a firefly habitat, it’s a display tree where adult fireflies go to do their flashing and find their mate.
“The actual area where females lay their eggs is on the ground along the riverbank.
“So, leaving a strip of berembang trees along the riverbank is not going to do the fireflies much good if the land behind that strip is destroyed,” said Nada Badruddin of the Forest Research Institute of Malaysia (FRIM).
Not all vegetation provides the same protection, however.
The institute, which studied the abundance and distribution of firefly larvae along the Selangor River, found that naturalised sago stands offer larvae the best survival rate.
The sago area has high decomposed plant material on the ground, which functions as a food source for snails that firefly larvae feed on. The condition also provides shelter to the larvae during the day.
Orchards and oil palm plantations, on the other hand, recorded low abundance of firefly larvae.
Bunds and the drainage system prevent river water from inundating the orchards and plantations, leaving the ground dry.
“This leads to food scarcity for the snails, making the areas less favourable habitats. “This finding highlights the negative impacts of plantation on the diversity of natural invertebrate populations,” said Nada, adding that almost half the area in Kuala Selangor has been converted into oil palm plantations.