Myrtle rust is found on Chilean guava on the Chatham Islands

Myrtle rust has been found on the Chatham Islands.

The  disease, caused by the invasive fungus Austropuccinia psidii, impacts plants in the Myrtaceae family (myrtles) including iconic New Zealand species like pōhutukawa. But  there are no endemic Myrtaceae on the islands and the find was made on the highly invasive Myrtaceous weed Chilean guava (Ugni molinae).

This has led Peter de Lange, a researcher with the Beyond Myrtle Rust programme, to believe there could be a silver lining to this discovery.

In late March, a member of the public brought a diseased plant sample to the Department of Conservation (DOC). The sample, which was confirmed as myrtle rust, was from the north end of the main island.

“Since myrtle rust is spread by wind and the Chatham Islands are downwind of New Zealand, its arrival was inevitable,” says de Lange, who had been surveying the Chatham Islands for myrtle rust before COVID lockdowns restricted travel out of Auckland. Continue reading