THE WALNUT ] 387 



The Walnut has few enemies in these Islands. The 

 mycelium of Armillaria mellea Val. may develop on 

 large wounds of the roots or of the base of the trunk, and 

 ultimately kills the tree. All such wound should be 

 painted over with tar. The larva or grub of the moth 

 Zeuzera pirina or Z. aesculi bores into the trunk or 

 smaller branches of the walnut, as it does in the case 

 of many other trees, and the tree is often grievously 

 damaged in consequence. The tendency of the grub is 

 to tunnel upwards, and usually can be reached and killed 

 by a bit of copper wire worked upwards through the 

 small hole in the bark by which the excreta of the grub 

 are shed. 



On the Continent the walnut is subject to the 

 ravages of the small beetle, Peritelus griseus OL, which is 

 7-8 m.m. long, of a black colour, spotted brown and grey. 

 This beetle eats off the young shoots in spring and 

 summer. Another small beetle, Bostrychus btcotor Hbst. 

 produces tiny but ramified tunnels under the bark, and 

 the well known May beetle (Melolontha vulgaris L.) is a 

 frequent parasite on the roots. Other beetles attacking 

 the trunk and main branches are Mesora curculionides L., 

 Saperda scalar is L., and Liopus nebulosus L. against 

 which it is recommended as a preventive to whitewash 

 heavily the bark on the stem and branches. 



A scale-insect, Lecanium juglavdis Bche., is common 

 on the walnut in Italy and Germany. 



The moth, Cossus ligniperda Fb. produces long 

 tunnels in the stem and branches, and when sufficiently 

 numerous may cause the death of the tree. Other moths 

 attacking the walnut in Italy are : Gracilaria fuglan- 

 della Mun. Dasychira pudibunda L . 1). fascelina L., 

 Bombyx neustria L., Amphypyra pyramidea L. and 

 Chetmatobia brumata L A species of Phytoptus, an 

 acatid, attacks both surface of the leaf, producing small 

 reddish galls ; and another acarid, Pkyllereus juglandis 

 Am., causes the erinosis of the walnut with its charac- 



