As the days get warmer, gardeners will be flocking to garden centres across Wales to buy plants and shrubs to smarten up their gardens.
High on their shopping list will be the trees and shrubs from all over the world that they have become accustomed to being able to buy locally.
But a plant health expert from the Welsh division of Forest Research, which is part of the Forestry Commission, is warning gardeners to be vigilant for any signs of pests that may have hitched a ride to Wales on their newly purchased plants.
Among these unwanted pests are two types of longhorn beetle from Asia that have been found several times in the UK on imported maple trees and within the packaging wood that is used to protect a wide range of goods.
These striking black and white beetles get their common name from their long antennae and, with these extended, they are each as long as the width of a credit card.
They are of considerable concern because they attack and can kill a wide range of broadleaved trees and ornamental shrubs. They have already become established in mainland Europe and now experts believe they could also establish here.
In the past, many pests simply died out after arrival in the UK because climatic conditions were unsuitable but today the effects of climate change are tending to increase the opportunities for pests to become established.
Dr Hugh Evans, Head of Forest Research in Wales, said, “Despite existing plant health rules to reduce the chances of pests making their way to the UK, some still get through and can have severe effects on our woodlands and gardens.
“While the enormous variety of plants at our garden centres boost global trade and give us choice and unprecedented availability, it is not always appreciated that living things, especially pests and disease organisms, may also be moved along these trade routes.
“Our changing weather conditions suit the pests themselves and, in addition, potential host trees are increasingly stressed due to higher summer temperatures and lower rainfall, making them more vulnerable to pest attack.”
Here in Wales, along with the rest of the UK, the sea barrier reduces natural invasions and a range of measures is in place to reduce human-assisted pest arrivals.
Dr Evans added, “Keeping pests out is the most effective strategy, but early warning of new infestations on our trees and plants is the next step; vigilance is vital in this process.
“Anyone who spots signs of infestation on any trees they buy should contact their local Fera Plant Health and Seeds Inspector for advice on what to do.”
More information on the longhorn beetle and other pests can be found on the Forestry Commission website – www.forestry.gov.uk – or on the Food and Environment Research Agency website – www.fera.defra.gov.uk.
