For decades, beekeepers have battled Varroa destructor – the mite that has crippled honey bee colonies worldwide. But now an even more dangerous threat is on the horizon: Tropilaelaps mercedesae – or simply “tropi”. Faster, deadlier, and harder to control, tropi could wreak havoc on honey bees – and on the billions of people who depend on bee-pollinated crops.
From Asia to Europe
Tropi’s natural host is the giant honey bee (Apis dorsata), found across South and Southeast Asia. But it didn’t stay there. The mite jumped to the western honey bee (Apis mellifera) – the species managed by beekeepers globally – and that changed everything.
Now, with this new host spread worldwide, tropi is on the move. It’s already been detected in Ukraine, Georgia, and southern Russia, and is suspected in Iran and Turkey. From there, the path into Eastern Europe looks inevitable – with Australia and North America also firmly at risk.
Why tropi spreads so fast
Like varroa, tropi breeds inside capped brood cells – feeding on developing pupae and transmitting deadly viruses such as deformed wing virus. But here’s the kicker:
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Varroa can survive for weeks on adult bees.
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Tropi can’t. It only lasts a few days outside brood cells.
That makes tropi desperate – constantly racing across the comb to find new larvae to invade. And that speed may make it far more destructive than varroa ever was.
https://phys.org/news/2025-09-deadlier-varroa-honey-bee-parasite.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter