52 HOPS. 



yellow spot, on the stems and leaves of the hop ; Hendersonia 

 Lupuli Moug., forming small black patches on the bine and 

 laterals. Among the phanerogams, Guscuta europcea L. occa- 

 sionally appears as a parasite in hop gardens, but does very 

 little damage. 



Animal Enemies of the Hop. 



The animal foes (vermin) attacking the hop plant belong 

 to various famihes. Some of them confine their ravages to 

 the roots, whilst others gnaw the leaves and stem, and others 

 again devote their attention to the cones. Although the 

 injury done by some of them is of little practical import- 

 ance there are others whose presence may place the crop 

 in jeopardy. 



1. The field mouse (Arvicola amphibius) fortunately is not 

 often met with in hop gardens. Nevertheless a single animal 

 will do a deal of injury by damaging, or even biting through, 

 the roots in burrowing. The damaged plants are easily 

 recognisable by their leaves withering and drooping. Put- 

 ting down phosphorus pills, or oats treated with strychnine, 

 will dispose of the enemy, but the object in view will be 

 accomplished with more certainty by laying in wait and 

 shooting them. 



2. The larvae of the cockchafer or May bug (Melolontha vul- 

 garis) gnaw the roots and underground runners ; the damage, 

 however, only becomes serious when the grubs are present in 

 large numbers. The best means of prevention is by catching 

 and killing the grubs when the ground is being hoed and the 

 first shoots cut, and by catching the fully developed beetles. 



3. The small larvae of Serica holosericea Scop, also feed 

 on the roots. 



4. More serious damage is done by the " wireworm " (the 

 larva of the click beetle, Agriotes lineatus L.), which feeds on 



