first time that an alien species has been used in Britain in this way. Scientists at the Commonwealth Agricultural Bureaux International do not believe the lice will cause any environmental damage. Over-grazing caused by the large numbers of Red Deer and sheep has also resulted in the impoverishment of moorland and upland habitats and a loss of native woodland. In 2012, the Scottish Government published a "Code of Practice on Non-Native Species" to help people understand their responsibilities and provide guidance as to which public body has responsibility for the various habitats involved. Deciduous trees Only 31 species of deciduous tree and shrub are native to Scotland, including 10 willows, four whitebeams and three birch and cherry species. The Meikleour Beech hedges located in Perth and Kinross were planted in the autumn of 1745 by Jean Mercer and her husband, Robert Murray Nairne. This European Beech hedge, which is 530 metres (0.3 miles) in length, reaches 30 metres (100 ft) in height and is noted in the Guinness World Records as the tallest and longest hedge on Earth. The Arran Whitebeams are species unique to the Isle of Arran. The Arran Whitebeam (Sorbus arranensis) and the Cut-leaved Whitebeam (S. pseudofennica) are amongst the most endangered tree species in the world if rarity is measured by numbers alone. Only 236 S. pseudofennica and 283 S. arranensis were recorded as mature trees in 1980. The trees developed in a highly complex fashion involving the Rock Whitebeam (S. rupicola), which is found on nearby Holy Isle but not Arran, interbreeding with the Rowan (S. aucuparia) to produce the new species. In 2007 it was announced that two specimens of a third new hybrid, the Catacol Whitebeam (S. pseudomeinichii) had been discovered by researchers on Arran. This tree is a cross between the native Rowan and S. pseudofennica. Shakespeare makes reference to Birnam Wood being used as camouflage for Malcolm Canmore's army before the battle at Dunsinane with MacBeth. There is an ancient tree, the Birnam Oak, standing a few hundred metres from the centre of Birnam. It may well have been part of Birnam Wood at the time of the battle 900 years ago, and remains part of the legend. Research into the possible commercial use of Sea Buckthorn was undertaken by Moray College commencing in 2006. The orange berries can be processed into jams, liquors and ointments and the hardy species grows