The bark beetle, which has destroyed thousands of trees in Perth, Australia, now threatens green spaces across the country.
A study by Curtin University has shown that a significant part of the continent provides suitable conditions for this pest. The polyphagous shot hole borer — a tiny beetle from Southeast Asia — not only bores tunnels but also introduces a fungus into the wood that clogs the vessels through which water and nutrients flow. Branches dry out, become brittle, and die off.
In Perth, the pest has already affected over 100 species of plants, including popular street trees. Now, plane trees in Melbourne, figs in Sydney, poincianas in Brisbane, as well as orchards with avocados, citrus, and mangoes are at risk.
The natural spread of the beetle is slow — about three kilometers per year, but humans transport it much faster: with firewood, mulch, and seedlings. Authorities have acknowledged that eradicating the pest is technically impossible — chemical treatments do not penetrate the fungal plugs. The only option left is to cut down infected trees at the edges of the outbreak.
$2.17 million has been allocated for research, but this is not enough. The country's biosecurity has cracked, and now even the ordinary transportation of firewood could spark a new outbreak.
