THE HOP PLANT. 57 



the leaves, the washing must be performed in a very careful 

 manner if good results are to be obtained. Picking off the 

 leaves in good time and burning them has also done good 

 service in many cases. 



The spiders hibernate in their webs in sheltered places, a 

 few of them remaining in cracks of the stems, and also in 

 the ground itself. 



It is of importance in tbe eradication of the pest that all 

 remains of hop plants should be destroyed after the harvest, 

 the soil and stocks strewn with lime, and the poles treated 

 in a suitable manner. Strebel recommends brushing the 

 latter over with alum solution, and considers that immersion 

 in water for about "a fortnight will also do good. Wagner 

 looks upon the poles as a refuge for spiders, and recommends 

 the use of wire frames as a preventive. 



2. Cosmopteryx eximia Hw. {C. Drurella St., C. Zieglerella 

 Hb.), the hop miner moth. The small larva of this butterfly 

 bores into the leaves and excavates the tissues, filling up the 

 devoured spaces with a fine web. The insect appears in July 

 and August, and the larvae change into the pupal condition 

 on the under side of the leaves. Collecting and burning the 

 leaves and tendrils affords the sole effective remedy. 



3. The larva of Gracilaria fidella Beutti. injures the hop 

 in a similar manner to the foregoing. It appears in June 

 and July, and changes into the pupa on the under side of 

 the leaves, ox occasionally rolls up the tips of the leaves 

 like a screw of paper. 



4. A less frequent pest is the larva of Agromyza frontalis 

 Mg., which mines the leaf from the tip. 



5. Limax agrestis L., the common field snail, eats holes 

 in the leaves, and betrays its presence by the slime it leaves 

 on the plant. Putting down cabbage leaves for bait and 

 surrounding the garden with a protective belt of powdered 

 lime or copper sulphate (blue vitriol) about 40 inches in width 



