Growing demand for healthy organic food has brought Britain a fly in the ointment – a big rise in deadly spiders.
Creatures such as black widows, whose bites are 15 times more venomous than rattlesnakes, are arriving in growing numbers by hitching rides in food cargo.
Shipments of grapes from the US caused a particular spike in the menace, according to evidence to MPs.
Spiders and other creepy-crawlies are deterred or killed by chemicals sprayed on most crops.
But because organic food is not treated with pesticides the bugs survive to be whisked halfway round the globe.
More arrive here in containers holding dogs and other animals brought from warmer countries including Australia.
The revelation came from Rob Quest, head of Heathrow Animal Reception Centre which deals with live creatures passing through the airport.
He said: “The number of black widows we had coming in increased substantially when we went to organic grapes from California.
As soon as they start bringing in organic food all those invertebrates survive. Stowaways are common.”
Mr Quest was giving evidence to an inquiry by the Environmental Audit Select Committee into invasive species.
The Heathrow centre seizes animals brought in illegally or unintentionally, including species which damage the native ecosystem if they get loose in the wild.
Black widows thrive in hot regions worldwide.
They rarely kill humans because the amount of venom they inject is so tiny but their bites are very painful.
There have been a number of instances of UK shoppers finding them in grapes.
