POPLARS: FUNGI AND INSECTS 371 



tecting species in frost localities on dry soils ; but, on moist 

 soils, the White Poplar is much more valuable. 



The Aspen is often very difficult to get rid of, and its 

 quick-growing root suckers often interfere with more valuable 

 trees. 



THE LOMBARDY POPLAR. 



This is not a native tree. 



The timber is of less value than all the other Poplars 

 described, and the stem is usually somewhat corrugated, and 

 there is much waste in conversion. 



It should never be planted from a sylvicultural point of 

 view. 



Of Fungi. Melampsora pinitorqua produces a rust on 

 the leaves of Aspen Poplars, and sometimes on the leaves of 

 the White and Grey Poplars. 



Little harm is directly occasioned thereby, but this 

 Melampsora is an alternate generation of the Caeoma Pine- 

 torquum, which injures the leading shoots of Scots Pine. 



Other species of Melampsora produce a rust on various 

 Poplars : e.g., M. larici tremula (on Aspens), or M. larici 

 populina (on Black Poplars), which is the alternate generation 

 of Cceoma laricis. 



Polyporus sulphurous causes Red Rot in the- timber of 

 Poplars. 



Of Insects. The larvae of the Cossus Ligniperda, or Goat 

 Moth (so named on account of its vile odour), damages the 

 timber. 



The timber is also much damaged by the larvae of the 

 Large Longicorn Beetle ( Cerambyx carcharias). 



The larvae of the Small Poplar Longicorn Beetle (C. 

 populned) attacks the branches. 



The larvae of the Satin Moth (Bombyx salicis) and the 

 beetles and larvae of the Red Poplar Leaf Beetle (Lina 

 populi] and of the Aspen Leaf Beetle (L. tremula) feed 

 upon the foliage. 



Mistletoe is very frequently found on Poplars. 



