Fireflies turned off by sprawl of city lights

Once common, but now hard to find

Uamdao Noikorn

Unplanned urban expansion is the death of fireflies, which are now largely unknown to most city dwellers, scientists say.

Contrary to popular belief, fireflies are not picky creatures requiring particular trees or feeding on particular food.

All they require is a small, clean pool of water, and some trees to rest in and spawn, a recent study found.

Impossible as that may seem in bustling Bangkok, fireflies can be easily found on the island state of Singapore and even in heavily populated Japan, thanks to rigid regulations on urban environmental management and city planning.

“We don’t know how much the firefly population has declined compared to the old days, but it seems quite significant,” said Sommai Chunram, chief of insect taxonomy at the Department of Agriculture.

Old literature always mentioned fireflies as children’s favourite toys and the most popular thing on river trips, “rare but not too hard to find”, she said.

“When we did this study, we went to popular firefly spots as well as places selected in random. There are still some of the insects to be seen though the number depends on the season and food source,” Mrs Sommai said.

The study, the first in Thailand, was inititated three years ago by Her Majesty the Queen under the Botanical Project in Chiang Mai.

The more project scientists learned about vegetation frequented by the bugs, the more they noticed their scarcity.

Entomologists from four major regions were then assigned to look into this beautiful creatures life and behaviour and compile a knowledge base for a programme to save them.

To their surprise, they found Thailand has over 100 species of firefly.

Mrs Sommai, who is in charge of research in the central and eastern regions, said some species can be found only in brackish water, and others in fresh water. Some have specific foods and others do not.

She said unplanned urbanisation was the biggest factor in killing off the firefly population.

“Many trees along waterways have been cut down, sometimes most unnecessarily,” Mrs Sommai said.

Fireflies lay eggs on branches and twigs near water, but too much light from the city drives them away.

“The problem is they can’t survive without water and and food,” she said.

The flickering light we see in the air is emitted by the mature bug, which lives for only one week, looking to mate and feeding only on water.

For now, the nearest places to admire fireflies are Ayutthaya and Samut Sakhon, in particular, where the Mae Klong river runs through riverside villages which still retain much of Thai traditional lifestyle-serene, little light and vast green areas. Also Samut Songkram.

“Fireflies were once part of our everyday life. Their disappearance means our development is not going in the right direction,” Mrs Sommai said.