58 HOPS. 



are good preventive methods. Similar injury is caused by 

 Helix nemoralis L. 



6. The grub of the hop vine snout moth, Hypena rostralis 

 L., dwells underneath the leaves, which it devours, leaving 

 only the skeleton network of veins. This pest appears early 

 in the spring, and continues eating until August, so the 

 damage done may sometimes be enormous. The best 

 palliative treatment is to shake the larvae off and collect 

 them. 



7. The caterpillars of Vanessa Jo L., the peacock butterfly, 

 and Vanessa G. album L., the white C. butterfly, are of less 

 frequent occurrence, and on this account do little damage, 

 though they devour the leaves. They are very conspicuous, 

 and therefore easy to collect. 



8. The larvae of Dasychira pudibtmda L., the beech moth 

 (crimson tail), are comparatively' rare, and do little damage. 



9. The grass-green caterpillar of the fleabane owl {Mames- 

 tra persicarics), which also occurs on hemp, peas, tobacco, etc., 

 is a nocturnal and leaf-devouring pest, but the harm done 

 is inconsiderable. 



10. Brotolomia meticulosa L. and Plusia gamma L., the 

 gamma moth, both of which in their larval stage are leaf- 

 devourers, are seldom met with in hop gardens. 



11. Aphis humuli Schr. {Phorodon humuli), the hop louse, 

 already referred to as the generator of animal honey dew, 

 sucks the under side of the leaves and the young shoots. It 

 appears in May, and increases at a very rapid rate, about 

 five milliards of aphides — according to Reaumur ^ — being de- 

 scended from a single female in the course of a summer. 

 Both winged and wingless forms are known. The first brood, 

 hatching out in the spring — on many sides it is alleged that 

 the perfect insect lives through the winter — begins the work 



' Strebel, Handbuch des Hopfenbaues, 1887. 



