From Dungun to Leiden: For the love of fireflies

This post is written by Dr. Wan Faridah Akmal Jusoh, Research Fellow at LKCNHM, for the Vereniging Nederland-Maleisie Newsletter (article republished with permission).

I was born and raised in Dungun, a beautiful coastal district of the north-eastern peninsular Malaysian state of Terengganu. Unlike what you are probably imagining, I did not grow up by the shore; instead, I spent most of my childhood in an oil palm plantation where my father worked as a plantation officer. I remember roaming among the palms around the house with my siblings, fishing in the canals and picking wild edible mushrooms with my father. Animals and plants have fascinated me ever since I was very young, but it wasn’t until the final year of my undergraduate studies that my fascination with biodiversity manifested as a passion for fireflies.

My introduction to fireflies happened in 2006, in Kuala Sepetang, a coastal town of the north-western peninsular Malaysian state of Perak. I was to start my first independent fieldwork experience in intertidal mangrove forests, and it got me hooked on fireflies. Since then, I started exploring fireflies from multiple aspects: ecology, taxonomy and evolution. After nearly a decade, these beetles (contrary to their common name, they are beetles, not flies) continue to hold my passion.

Fast forward to 2019, I received an invitation to visit Leiden, a beautiful city famous for arts and science in the Netherlands. In the heart of Leiden is Naturalis Biodiversity Center – a brand-new museum – one of the world’s top five natural history collections. So there I was in Naturalis for three weeks on one important mission: to discover collections of fireflies from Southeast Asia. The visit caused a few raised eyebrows from the start. “I didn’t know we had fireflies in the Naturalis collections”, said people whom I have spoken to. Well, neither did I.

Fireflies of Southeast Asia go to Europe

Scientists working on fireflies in Southeast Asia still mostly live in the dark with species discovery. Literature or records of species from this region were mostly produced in the 19th century. They are not easily obtainable and are usually in Latin, French or German, making them hard to understand for local SE Asian researchers.

On top of that, the name-bearing, or type specimens of SE Asian species are not usually preserved in local collections. When describing a species, the taxonomist involved chooses a preserved individual to act as the ‘name bearer’ for that species (e.g. Pyrocoelia straminea Olivier). Therefore, the type serves as the representative of a species, much like a definition of a word in a dictionary. Without a type specimen or a precise description of the type specimen, taxonomists cannot reliably determine if other specimens in their possession belong to the same species – that is how important types are.

For fireflies, many important type specimens are in the Muséum national d’Histoire naturelle in Paris owing to work by two prolific taxonomists: Ernest Olivier and Maurice Pic who made numerous species descriptions from all over the world. If not in Paris, one would assume that the specimens should be in the Natural History Museum in London, where most of SE Asia’s important natural history materials are likely to be housed.

So why was I making the trip to Leiden?

In October 2019, the monograph on fireflies of SE Asia and the Australopacific region by Dr Ballantyne and co-authors (including myself) revealed a list of 222 species! We acknowledged that there are some undetermined species because we could not locate the type specimens. In the monograph, we also discussed how many collections from Indonesia have not been studied since the species were described.

I realised that perhaps we never found the specimens because they could be in Leiden and I, myself, never had the opportunity to look for them there. It is fair enough to say that we know only of one Dutch taxonomist (Mr. Ritsema) of significance, but in our defence, specimen exchanges between museums in the era of cabinet of curiosities in the 1800s were so active that it was possible for an important specimen might be in Leiden. If we look back on the history of the Netherlands in SE Asia, it would not be surprising that we might find something valuable in Leiden. Why not give it a go, I thought?

From Leiden back to Southeast Asia, digitally

What we found far exceeded my expectations. With the help of Naturalis’s curator Dr Hans Huijbregts, I found at least 30 type specimens of fireflies from SE Asia. Not only that, I also found a type specimen previously believed to be missing, Pteroptyx decolor Olivier from Atjeh (Aceh). In addition to hundreds of previously unexamined specimens of fireflies, we found some drawers we believe unopened since a prominent Swiss beetle taxonomist Dr W. Witmmer sent them to Leiden. Seeing these unidentified specimens in a dozen of drawers was like receiving a dozen of boxes of chocolates. I didn’t know what I would get.

As of 17 December 2019, all type specimens have been digitised (thanks to Mrs. Yvonne van Dam for her kind assistance) as high-resolution images for collection inventory and should be digitally accessible to all soon, including taxonomists in SE Asia. I am now in collaboration with Dr Ballantyne and Dr Huijbregts to re-examine some types to figure out if they are valid species. Who knows, there might be one or more new species recorded?

All in all, I think we are making good progress, because after nearly 200 years in Naturalis’s cabinets these important collections of fireflies from SE Asia (as well as other countries in Indo-Pacific region) have been discovered and are waiting to give up their secrets! I have discovered that loving fireflies and natural heritage connects me to love of my heritage. In the age of anthropogenic climate change and environmental degradation, we must not take fireflies or natural history for granted.