138 THE HOP. 



sage-brush land. Nevertheless, on account of the ex- 

 pense of spraying in western Washington, Professor 

 Piper is of the opinion that hop growing will never 

 again become the industry that it was prior to the 

 introduction of the louse. There is some prevalent 

 opinion in Washington that the life history given in 

 preceding sections will not hold for that part of the 

 country. Growers claim that winged lice occur 

 throughout the season and they do not believe that all 

 the winter eggs are deposited on prune or plum trees. 

 This statement seems extremely improbable to the 

 writer, but it must be stated that no observations have 

 been made in that part of the country which are at all 

 comparable with the extremely careful ones carried on 

 in New York in 1887. Nevertheless, Mr. Koebele, when 

 in Oregon in 1893, "^^as able to set at rest one of the local 

 misapprehensions, which was to the effect that the hop 

 louse occurs also on one of the mints. He sent speci- 

 mens of the insect to the city of Washington, where, 

 upon examination, it was found that although the 

 resemblance was extremely close, the mint insect 

 belonged to a different species of the same genus, 

 Phorodon. 



The hop plant louse made its first appearance in 

 the Wisconsin hop discrict in 1867-68, and from that 

 time on was more or less abundant every season, some 

 years almost entirely destroying the crop, and in others 

 causing only partial loss. Its attacks have practically 

 ruined the hop industry of the state. 



THE HOP GRUB OR HOP-PLAXT BORER 



{GorUjna immanis, Grt.) 

 This insect probably ranks second in importance 

 among those which we shall mention, although of late 

 years it has been vastly less destructive than the plant 

 louse. It is a distinctive North American insect and is 

 known as a hop pest cnly in the east. The moth has 



