INJURIOUS ANIMALS. 77 



of nature, by disintegrating, removing, and destroying wood that 

 is already decayed, just as the ship-worms rid the seas of much 

 derelict timber. The termites will, however, attack most species 

 of wood after conversion, sometimes eating their way upward 

 from the foundations of a house to its rafters until all its timbers 

 are reduced to a mere shell, or completely destroying wooden 

 articles of furniture. The pungent resinous secretions which repel 

 the teredo seem also generally effective as a protection against 

 termites. 



The large and voracious larvae of some moths are most destruc- 

 tive to growing trees, and sometimes attack converted timbers. 

 Very generally their eggs are laid in the bark, and the grubs 

 generally bore downward through the sapwood. The Goat-moth 

 (Cossus lignipe'rda), for instance, specially attacks aged and already 

 unsound Willows, Ash, and Elm; but will attack converted as 

 well as living wood. The Wood-leopard (Zeuzera cesculi) specially 

 attacks living fruit-trees and Horse-chestnuts, and its Australian 

 congener, the Wattle Goat-moth (Z. eucalypti) frequent the various 

 species of Acacia. Such insects are most destructive ; but their 

 large galleries are only too obvious in converting timber. Of the 

 wood-boring beetles, on the other hand, many only attack 

 unhealthy trees : others, such as Scdlytus destructor, the Elm-bark 

 beetle, tunnel in and under the bark, especially of fallen logs, 

 only occasionally penetrating a small depth into the outer wood. 

 Others are far more destructive, in many cases mainly attacking 

 sound converted timber. The widespread Death-watch beetles, 

 for instance, (Anobium domesticum, A. tessellation, and allied forms,) 

 the chief cause in England of the familiar " worm-holes " in Oak, 

 frequently entirely destroy the timbering of roofs, and still more 

 commonly riddle our smaller articles of furniture. In the Tropics 

 and warmer Temperate regions their place is largely taken by the 

 numerous family Bostrychidce, some of which attain far larger 

 dimensions. 



