We have kindly received this advice note from Beatrice Potter who is alerting us to a new invasive species of moth that destroys box plants.  

 The larva will defoliate box plants practically completely and there are no natural predators in the UK.

For full details from The Royal Horticultural Society

From RHS “This species has become established and is spreading, and has the potential to have an impact on native populations of Box and disfigure ornamental Box hedgerows and topiary. However, where control is being considered, the use of pesticides should be avoided. Where bushes are small we encourage the removal of the larvae by hand. However, it is realised that this approach is unlikely to be appropriate where large, older topiary bushes are involved. In these circumstances the mixed nematode biological control which is sold as Fruit and Vegetable Protection should be tried in the first instance and may have some impact, being careful to follow the instructions. As a last resort spraying, using a pesticide, may well be considered, although we strongly advise against using any neonicotinoid pesticides currently available. Bear in mind that pesticides available will not be specific to Box Moth and will kill other non-target species of invertebrate, including butterflies and moths. Therefore, if spraying is considered the only option then this should be undertaken with extreme care. Still weather conditions should be selected, with just the target bush sprayed, avoiding any spray falling to the ground or any spray drift to neighbouring plants or grasses. Bushes in flower should not be sprayed as this could be harmful to pollinating insects. Where large numbers of larvae have occurred, vigilance is likely to be required as reinfestation is quite likely. Ultimately, consideration should be given to plantings other than Box. Finally, new plantings of Box should be carefully considered and, where this is planned within the range of this moth, alternative plants (preferably native) should be considered. July 2017 (updated November 2018)”