The alert was raised after one man died near the French capital after being stung by the Asian hornet Vespa velutina, which is four times the size of native honeybees.
The victim had disturbed a nest while pruning a hedge in the village of Coron.
The invasive species is thought to have arrived in southwest France in 2004, hidden in a delivery of Chinese pottery.
It has since colonized a large swath of France, and could soon be blown or carried across the English Channel to infest Britain.
“We have modeled its potential spread by cross-checking data from France and Asia, and concluded it is capable of living anywhere in Europe and certainly in Britain,” Paris’ Museum of Natural History expert Frank Muller told The Telegraph.
Vespa velutina can kill up to 40 bees in a minute. A few of the insects can destroy a hive of 30,000 bees within two hours.
Honey production has plummeted in the 39 of France’s 100 administrative departments where the hornet has arrived.
Groups of the invaders hover in front of beehives, picking off individual bees, and then decapitating them and stripping off their wings and legs. They then head to their own nests with a bee “meat ball” to feed their young.
Photo: BlueGinkgo - Wikimedia Creative Commons