22.10.2021

Lord Howe Island stick insect found after extinction

The species disappeared from its home on Lord Howe Island in New Zealand after a shipwreck introduced black rats into the island’s ecosystem.

It was thought to have gone extinct in 1918, but an insect discovered in the 1960s has been identified as a Lord Howe Island stick insect.

But the discovery suggests that a few individuals must have survived, and researchers now hope to reintroduce the species back into its native home on Lord Howe Island.

It was thought to have gone extinct in 1918, but an insect discovered in the 1960s has been identified as a Lord Howe Island stick insect

REDISCOVERING THE STICK INSECT

The remains of a stick insect was discovered in the 1960, and several more were found nearby in the early 2000s.

But until now, there has been some doubt over whether the stick insects were the same as the thought-to-be-extinct Lord Howe insects, because of their differing looks.

Now, researchers have used genetic analysis to confirm that the insects are indeed the same species as Lord Howe Island’s.

To prove this, the researchers sequenced the mitochondrial genomes of captive-bred Ball’s Pyramid island stick insects and preserved Lord Howe Island stick insects.

When comparing the genomes, the researchers found that the DNA diverged by less than one per cent – to showing they are the same species.

Rock climbers on Ball’s Pyramid in the 1960s discovered the freshly dead remains of a stick insect, and several more were discovered nearby in the early 2000s.

But until now, there has been some doubt over whether the stick insects were the same as the thought-to-be-extinct Lord Howe insects, because of their differing looks.

Now, researchers from the Okinawa Institute of Science and Technology Graduate University have used genetic analysis to confirm that the insects are indeed the same species as Lord Howe Island’s.

To prove this, the researchers sequenced the mitochondrial genomes of both captive-bred Ball’s Pyramid island stick insects, as well as preserved Lord Howe Island stick insects.

When comparing the genomes, the researchers found that the DNA diverged by less than one per cent – enough to show that they are the same species.

Professor Alexander Mikheyev, lead author of the study, said: ‘In this case, it seems like we’re lucky and we have not lost this species forever, although by all rights we should have.

Until now, there has been some doubt over whether the Ball’s Pyramid stick insects (pictured left) were the same as the thought-to-be-extinct Lord Howe insects (pictured right), because of their differing looks

The researchers sequenced the mitochondrial genomes of both captive-bred Ball’s Pyramid island stick insects (pictured), as well as preserved Lord Howe Island stick insects

‘We get another chance – but very often we do not.’

Following the findings, the government is now supporting plans to eradicate black rats from Lord Howe Island and reintroduce the stick insect species.

The researchers hope their findings will act as a larger message related to conservation.

When comparing the genomes, the researchers found that the DNA diverged by less than one per cent – enough to show that they are the same species

Professor Mikheyev said: ‘The stick insect story illustrates the fragility of island ecosystems, and in particular, how vulnerable they are to manmade change like invasive species’

‘It just took one shipwreck, and the fauna of the island has been altered in such a fundamental way.

‘Unlike most stories involving extinction, this one gives us a unique second chance.’

Following the findings, the government is now supporting plans to eradicate black rats from Lord Howe Island and reintroduce the stick insect species

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