INJURING THE BRANCHES. 



147 



through a sharp-pointed beak which is inserted into 

 the bark of the succulent twigs, and also into the 

 leaves. It has comparatively few natural enemies. 

 Remedies. — These bugs may easily be destroyed 

 when gathered in clusters on trees or walls by pour- 

 ing boiling water, gasoline or kerosene upon them. 



INJURING THE BRANCHES. 



The Spotted Willow-twig Aphis. 



Mdanoxan thus salicis. 

 The various species of willow are particularly sub- 

 ject to the attacks of aphides or plant lice. No less 



than nine of these insects 

 have been described as 

 preying upon them. No 

 part of the tree, except, 

 possibly, the root, is ex- 

 empt from attack, and the 

 bark and twigs receive the 

 exclusive attention of at 

 least five species. Some of 

 these often become seri- 

 ously injurious, and more 

 frequently, perhaps, their 

 presence is extremely an- 



Fig. 74. Spotted Aphis : oviparous . , , 



• female. Magnified. llOVing where they OCCU1' 



upon shade or ornamental trees in private grounds 

 or public parks. 



The aphides most commonly found upon willow 

 twigs belong to the genus Melanoxanthus. Three 



