Moth watch Gardeners urged to watch out for destructive insect
GARDENERS in the county are being urged to look out for a destructive moth. Green thumbs in the county should report any sightings of the Cydalima perspectalis, otherwise known as the box tree moth, which lays its eggs on the underside of box leaves between April and October.
The box tree moth only arrived in the UK in 2007, but just 13 years later, the damage caused to box hedging is spreading across the country at an ‘alarming rate.’
The moth descends from Japan, China, Taiwan, Korea, India, and fareast Russia, but is making more and more of the UK its home.
Although the moth population is much higher in London and the South East, there are reports from further north every year - with some reports as far north as Newcastle-upon-tyne and the Leeds area.
In 2018, it was first reported in the Fife area of Scotland. It has also been reported in several parts of Wales.
Now, it has been reported in Gloucestershire.
When the caterpillars emerge from their eggs, they rapidly strip the foliage from large areas of hedging and topiary features.
September and October are the best time of year to treat plants as they will be protected from hungry caterpillars throughout the winter.
Gardeningexpress.com and BASF have developed a map, where you can check to see where box tree caterpillars and moths have been spotted.
Cheltenham has been featured on the map recently, with several being caught in traps in the GL50 area earlier this month.
Gardeningexpress.com said in a statement: “In their prime from April to October, box tree caterpillars feed within webbing and can completely destroy all of the foliage on box plants.
“To stop the damage, remove the caterpillars by hand.”
Plants afflicted by a box tree moth invasion can be treated with the microscopic, naturally-occurring White Knight nematode.
It can be sprayed directly onto the leaves of the box plant with a hand pump sprayer when young caterpillars are on the foilage - as nematodes need to make direct contact with the pest in order to control it.
In terms of appearance, the box tree moth is described as ‘medium-sized’ and has purplish brown wings with a white spot near the centre of the forewing. You are likely to become aware of the box tree caterpillar when you notice pale yellow flattish eggs, which are laid in a sheet-like fashion, overlapping each other on the underside of box leaves.
Freshly hatched caterpillars can be identified as being of the box tree variety if they have greenish-yellow bodies with black heads.
The caterpillars consume box leaves and create webbing over their feeding area.
If you spot signs of box tree moth invasion on your box plant, then you can report this to Jon from Green Gardener at Jon@greengardener. co.uk