The Indonesian Island of Sulawesi was known to host some of the planet’s most enigmatic wildlife, including the tusked deer-pig babirusa. Now, researchers have discovered a trove of new insect life — so many that they had some trouble finding names for all of them. The names of Star Wars and Asterix characters were chosen to fill in the ranks of newly-discovered beetles.

The beetles

For all its amazing fauna, the insect diversity of Sulawesi has remained largely understudied.

“We had found hundreds of species on the neighboring islands of New Guinea, Borneo and Java – why should Sulawesi with its lush habitats remain an empty space?” asked entomologist and lead author of the study Dr Alexander Riedel, Natural History Museum Karlsruhe (Germany).

In fact, Riedel himself discovered a few interesting specimens all the way back in 1990 — specimens which would become the basis of the current study. Since then, Riedel has carried out several expeditions on Sulawesi,
in collaboration with the Indonesian Institute of Sciences (LIPI). Bit by bit, they found more pieces of the insect puzzle — but it wasn’t easy.

For starters, they are difficult to see. In the lush forests of Sulawesi, tiny beetles that measure 2-3 millimeters don’t really stand out. Secondly, identifying them is even more difficult.

Although DNA analysis shows that they are clearly different species, many of the newly discovered beetle species look quite similarly to each other. In fact, they look so similar to each other that DNA sequencing seems like the only method to tell them apart.

Lastly, the funding hasn’t exactly been flowing. There is only one full-time position for a beetle researcher at the only Indonesian Zoological Museum, which covers the entire Indonesian archipelago of over 17,000 islands, so international collaboration was key.

The researchers’ efforts were greatly rewarded, however, with over 100 new species discovered. Even so, the team says they’ve only begun to understand the tiny critters that lurk in Sulawesi.

“Our survey is not yet complete and possibly we have just scratched the surface. Sulawesi is geologically complex and many areas have never been searched for these small beetles,” said Raden Pramesa Narakusumo, curator of beetles at the Museum Zoologicum Bogoriense (MZB), Indonesian Research Center for Biology.

Naming 103 beetles

All of the beetles they’ve found are weevils, and furthermore, they all belong to the genus Trigonopterus — a genus of flightless weevil. Until 2013, only 90 Trigonopterus species were known, when a single paper doubled that number.

Coming up with as many as 103 novel names is not a particularly easy task either. At first, they used descriptive names or names associated with localities, but those ran up quickly — so researchers turned to popular culture for inspiration.

After childhood favorites Asterix and Obelix, they turned to the Star Wars character Yoda and to the mythological satyrs and the Greek goddess of hunting, Artemis. Other species pay tribute to famous biologists, including Charles Darwin (father of the Theory of Evolution), Paul D. N. Hebert (implementer of DNA barcoding as a tool in species identification) and DNA pioneers Francis H. C. Crick and James D. Watson.

The study also provides some information about the evolution of the
Trigonopterus. Sulawesi is part of Wallacea, a bio-geographical transition zone between Australia and Asia, which means it has fauna from both areas. Researchers now believe that Trigonopterus originated in Australia and only later reached Sulawesi, where it developed a thriving population. A group with only a few different populations was found to be capable of diverging into more than a hundred species in a brief period of time, something which researchers are currently analyzing.

Journal Reference: Riedel A, Narakusumo RP (2019) One hundred and three new species of Trigonopterus weevils from Sulawesi. ZooKeys 828: 1-153. https://doi.org/10.3897/zookeys.828.32200