Image copyright Alexander Riedel Image caption Trigonopterus yoda: A shiny green beetle named after the Stars Wars character

More than a hundred insect species that are new to science have been discovered on an Indonesian island.

Found in remote rainforests, the tiny beetles appear to have been overlooked for decades.

All 103 belong to the same group - weevils.

Scientists have named the creatures after Star Wars and Asterix characters, including Yoda, a green shiny beetle, and Obelix, a rather rotund specimen.

Others have been named after scientists, including Charles Darwin, and DNA pioneers, Francis Crick and James Watson.

The beetles are only a few millimetres in length. Only a single member of their insect group has been found before on Sulawesi - as long ago as 1885.

The island, known for its exotic wildlife, including birds and monkeys, is covered by lowland rainforests, although much of this has been cleared.

The researchers say there may be more of the beetles out there.

"Our survey is not yet complete and possibly we have just scratched the surface," said Raden Pramesa Narakusumo, curator of beetles at the Museum Zoologicum Bogoriense (MZB), Indonesian Research Center for Biology.

"Sulawesi is geologically complex and many areas have never been searched for these small beetles."

Image copyright Alexander Riedel Image caption Three beetles have been named after the French cartoon series Asterix: Asterix, Obelix and Idefix

The scientists say evidence points to thousands of undescribed insect species roaming the rainforests on the island.

However, this does not change the picture of recently reported declines in insects, which is connected to two issues, said entomologist Dr Alexander Riedel, of the Natural History Museum Karlsruhe, Germany, who worked on the study.

"The decline of insects that we currently discuss in Europe is presumably largely caused by intense agriculture and insecticides," he told BBC News.

"Whereas the wealth of insect biodiversity in the tropics is endangered by the destruction of rainforests."

Globally, well over one million species of insect have been described to date. Recent studies have suggested there is an ongoing dramatic decline in insect populations around the world.

Insect life is at the bottom of the food chain and underpins much of life on Earth.

Image copyright Alexander Riedel Image caption Mountain forest of Sulawesi, where some of the new species have been found

Dr James Hogan of the Oxford Museum of Natural History said the study highlights how much of biodiversity we have yet to discover and catalogue.

"In fact, when talking about biodiversity in reality what this means to a great extent is exactly what is described here - small insects less than 5mm long," he said.

"With biodiversity under increasing threat it is vital to do this kind of work before it's too late."

The beetles were identified by DNA sequencing, which is not always available to scientists in Indonesia.

They belong to the genus Trigonopterus.

The research is published in the journal, ZooKeys.

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