A scale insect with strings of eggs that make an unsightly wrapping around branches has been identified as the first new garden pest of 2019, experts have said.

The Royal Horticultural Society (RHS) said the cotton stringy scale (takahashia japonica) was found on a magnolia in Berkshire, which is thought to have been imported.

It is not currently thought to cause any problems for the host plant beyond the unsightliness of the egg masses, which resemble a white wrapping around the branches, the horticultural experts said.

If gardeners cannot bear the look of the bugs on their trees and shrubs they can remove them with a stiff brush and water.

The RHS is keen to hear from any gardeners who find the pest in their garden so it can build up a picture of the plants it is being found on, with magnolias, mulberries, elders, sycamores and dogwoods thought to be favourites.

Gerard Clover, head of plant health at the RHS, said: “The cotton stringy scale is the first new pest detected by the RHS in 2019.

“On average four are found every year but the global plant trade is exacerbating the spread of pests and diseases, and gardeners need to be alert to changes and maintain good plant health.

“Unlike some other pests we expect to find, the scale insect causes little to no damage to the plant but will undoubtedly cause some concern for gardeners.

“In spite of its odd appearance it could well be overlooked and more established than we think.”