Of Fireflies and Mangroves: Singapore Story

Before we get started, have you checked out this oh-so-adorable infographic already?

If you are surprised to find out how little we really know of fireflies in Singapore, you are not alone.

In celebration of our shores, Entomologist Lounge partners with Celebrating Singapore Shores to highlight fireflies in our mangroves, and how important one is to the other.

For quick crash course on Singapore’s fireflies, the Entomologist Lounge is very thrilled to have Dr Wan F.A. Jusoh from National University of Singapore (NUS), to share some bite-sized info on fireflies here.


“For the benefit of the clueless here, what is a firefly?”

Fireflies are actually beetles (from family Lampyridae). They are also known as lightning bugs or glow-worm. In Malay, they are either called “kelip-kelip” and “kunang-kunang” (hence the name of my blog kelipx2). They are small soft-bodied flattened beetles, usually between 1 and 2 cm. Fireflies have the ability to produce light of various luminance depending on species, life stages or even sex.


P valida

A screenshot showing Singapore’s Pteroptyx valida identified by Dr Wan. Source: The Biodiversity of Singapore website.


“How do fireflies earn their namesake?”

Fireflies produce light through a chemical reaction (a process called bioluminescence) from light organ (LO) located at the lower part of the abdomen. One can spot whitish or yellowish light organ at the second to last segments of abdomen. Fireflies use light to communicate with other members of the species, mainly as a way for mating.

Interesting fact

A male firefly has two segments of LO while a female firefly has one segment of LO.

At immature stage, firefly larvae use their bioluminescence as a warning signal to warn potential predators. And it is not a bluff – firefly larvae do have defensive chemicals in their body that give off bad taste!


Fireflies flashing at night. Photo by Mike Lewinski.


“Singapore is such a small country. Do we really have our very own fireflies?”

Yes, we do! There are at least 10 species of fireflies recorded from Singapore based on last surveys (2009-2010) by a group of Singapore researchers. I believe there are more species in the wild than what we have been recorded so far. For me, the most interesting species are of the genus Pteroptyx which is known to display aggregative flashing. Most species of this genus are actually found in mangroves. You can view some firefly species from The Biodiversity of Singapore here.

Fireflies Biodiversity Singapore

A screenshot showing Singapore’s firefly species. Source: The Biodiversity of Singapore website.


“Where and when can we see fireflies?”

In Singapore, fireflies can be found in diverse undisturbed habitats, particularly in warm and humid environments such as mangroves and freshwater swamps. A few species can be found hovering around bushes or green parks. Best time to see fireflies is right after sunset. Fireflies love humidity but not too wet, so your best chance to spot them is one or two hours after rain.


Look up for firefly adults’ flickering light. Look down to the ground for the larvae’s warning signals.


“Are fireflies here being endangered? What could be the cause?”

While we have yet to prove through studies on whether firefly population has been stable or declining, there is no doubt we have the risk of losing our fireflies soon due to destruction of their natural habitats. Fireflies have intricate relationship with forests where they inhabit. As forests disappear, and so will our fireflies.

Here’s a quick infographic about the status of Singapore’s fireflies, courtesy of kelipx2:



“How are fireflies important to our nature? What happens if we lose fireflies?”

Fireflies are often regarded as important indicators for environment because each life stage of a firefly species would require a different microhabitat.

This is why, in some countries, firefly larvae are used for biological testing of treated wastewater before the water is discharged into the sea and they are also useful as biological controls for invasive snail species populations.

Infographic firefly life cycle

Infographic: Why every bit of mangroves matters to every life stage of fireflies

If we lose fireflies, that indicates we are living towards unhealthy habitat – an endangered habitat.


Dr Wan FA JusohDr Wan F.A. Jusoh is a Research Fellow in Department of Biological Sciences, NUS. While her interest covers conservation biology (particularly in insect biodiversity and wetlands management) and digitalisation of specimen collections into biodiversity databases, she has an academic soft spot for fireflies. She writes passionately about her love life on kelipx2. When night sets in and duty calls end, Wan enjoys cooking, sci-fi movies, and travelling for her quiet rendezvous with fireflies.


If fireflies excite you, look forward to World Firefly Day this July 7th and 8th. Head over to Fireflyers International Network here to find out more.


© Jo-Lynn Teh, BCE


Jo-Lynn Teh is ESA Board Certified Entomologist based in Singapore. While her specialisation is on tropical insects that affect public health and agriculture, Jo-Lynn’s passion is also to help people understand insects. Find her on LinkedIn.


One thought on “Of Fireflies and Mangroves: Singapore Story

  1. Pingback: “Eh? We got fireflies in Singapore?!” | The Entomologist Lounge

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