HEMIPTERA 



97 



The grape-vine louse (Phylloxera vastatrix) is said to have 

 cost the French more than the indemnity paid to the Ger- 

 mans after the Franco-Prussian war. Its damage in this 

 country is not great. 



The hop louse (Phorodon humuli) is the great enemy of 

 the hop industry. Aphis rosce makes the raising of roses 



FlG. 105. Grape-vine Phylloxera ; a, adult ; b, young. After Marlatt. 



difficult in some regions. The maple louse blights young 

 maples. Aphis mail stunts many young apple trees. The 

 cherry aphis (Myzus cerasi) lives on the cherry from April 

 till June, and feeds on another plant the rest of the season. 

 The green pea louse along the Atlantic coast in 1900 de- 

 stroyed peas to the value of four millions of dollars. In 

 1899 the wheat louse damaged the wheat badly in many 

 sections. 



