AS millions of poinsettias are shipped out to shops around the UK for Christmas, government inspectors have been braving the snow in North Yorkshire to check the must-have pot plants of the festive season are free from a potentially devastating pest.
Supermarkets, department stores and garage forecourts are full of the brilliant red flowers at this time of the year.
But the plants, which are grown each year from imported cuttings, are prone to attack from the tobacco whitefly (Bemisia tabaci) - a tiny pest which carries more than 110 viruses.
These viruses are a particular threat to other plants grown under cover in the UK, especially tomatoes and cucumbers.
Inspectors from the Food, Environment and Research Agency (Fera) are now out touring greenhouses - checking seas of red poinsettias for signs of the fly.
About four million poinsettia plants are sold every year in the UK and about half of them are grown in this country from the imported cuttings.
Plant Health and Seeds Inspector Chris Snell said: "The real risk is the spread of the viruses to protected tomato and cucumber crops.
"We've seen evidence in places like Spain and Portugal where these viruses completely devastate the crop."
Today, Mr Snell was examining thousands of poinsettias at Ravensworth Nursery, near Richmond, North Yorkshire.
He said it was a tough season for growers as the greenhouses need to be kept at a relatively high temperature while air outside is, at the moment, exceptionally cold.
Fera said 12 cases of tobacco whitefly have been successfully intercepted and eradicated so far this year.
The inspectors begin work early in the growing process, around July or August, but continue until all the plants leave the growers.
This inspection regime is in place because the UK is currently designated by the European Union as a Protected Zone for tobacco whitefly.
A consultation process is due to take place over the next few weeks with all interested parties to decide whether this Protected Zone status should continue.