We know introduced honeybees as the ever-busy helpers of our gardens, farms and orchards.

In pollinating crops and fertilising fruit, they support more than a third of the food we eat and are worth billions of dollars to New Zealand’s economy.

But they could also be unwittingly helping one of the worst natural threats facing Aotearoa’s native forests: myrtle rust.

By collecting spores as food, then carrying them from plant to plant, honeybees may be under-appreciated vectors of this recently-arrived fungal disease.

Our recently published research adds further weight to this idea, challenging the assumption that myrtle rust spreads mainly by wind alone.

How myrtle rust hitches a ride

Indigenous to Central and South America, myrtle rust was first detected in New Zealand in 2017. Since then, it has spread across much of the North Island and into parts of the South Island and the Chatham Islands.

It attacks plants in the myrtle family, including treasured native species such as pōhutukawa, rātā and mānuka, as well as exotic species such as guava, feijoa, bottlebrush, lilly pilly and eucalyptus. It poses a particularly serious threat to vulnerable native plants such as ramarama and swamp maire.

As the disease has emerged in more places, researchers have been paying........

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