42 TOWN PLANTING 



especially such as are in an unhealthy con- 

 dition, the goat and wood leopard hioth (Coc- 

 cus ligniperda and Zeuzera cesculi), the Elm 

 bark beetle (Scolytus destructor), and Oak 

 leaf roller moth (Tortrix viridand) are 

 those that give most trouble in our larger 

 towns and cities. All these are plentiful in 

 London and frequently much damage has 

 been done and many fine old trees ren- 

 dered unhealthy, or killed out by their 

 depredations. The Elms suffer from the 

 attacks of the goat moth and bark beetle, 

 while the wood leopard moth has caused in- 

 calculable damage to Chestnut, Thorn, and 

 various members of the Pyrus family. Oaks 

 are frequently defoliated by the Oak leaf 

 roller moth which appears in certain seasons 

 in vast numbers and feeds on the leaves of 

 the tree. Where a large number of trees is 

 attacked little can be done, but in the case of 

 isolated standard specimens much good can 

 be brought about by spraying, hand-picking 

 and shaking the trees, the moths being col- 

 lected and destroyed. 



