QO BRITISH FOREST TREES 



and Gryllotalpa do great damage to the roots of seedlings 

 and young plants, whilst the beetles Hylobius abietis and 

 pinastri and Hylastes cunicularis gnaw the tender bark of 

 their stems ; later on the cortex and sap-wood suffer from both 

 the larvae and the fully-developed beetle of three varieties 

 of Bostrychus amitinus, chalcographus, and typographies, 

 whilst the mature wood is damaged by both the active 

 forms of Xyloterus lineatus. Buds and foliage are destroyed 

 completely, and valuable forests utterly ruined over immense 

 tracts of country, by that scourge of the coniferous forests of 

 Germany, Liparis monacha, the voracity of whose caterpillars 

 is only equalled by their almost unlimited numbers in bad 

 years like 1889, 1890, 1891 in southern Bavaria, where alone 

 the extent of forests devastated by the black arches, " nun," 

 or spruce moth (Liparis monacha] is estimated to be about 

 42,500 acres or sixty-six square miles, of which by far the 

 greatest portion was pure forest of spruce. 1 In the mixed 

 forests attacked, the beech and Scots pine suffered compara- 

 tively much less than the spruce, although they were also badly 

 injured ; the spruce, however, was usually killed outright, 

 owing to the much smaller reserves of starchy matters stored 

 up by this species for subsequent constructive purposes. 



In recuperative power with regard to injuries received, 

 whether caused by insects or by deer, the thin-barked 

 spruce is not well endowed. Where a strong head of game 

 is maintained, red-deer do more damage in spruce forests 

 than elsewhere, by stripping the bark with their teeth during 

 summer, as well as for food during winter. The damage 

 caused is often very serious, and is generally most wide- 

 spread in pole-forests from twenty to forty years of age, 

 although it is often done also in tree-forests up to sixty 

 years of age. For the healing of the wounds thus caused, 



1 For a detailed account of this insect and its ravages, see the 

 Transactions of the Highland and Agricultural Society for 1893. 



