BOMBYX PUDIBUNDA. 307 



prefers dry, sunny, elevated places, and avoids valleys. It has 

 often been noticed that an attack commences simultaneously 

 at several points of high elevation, from which it spreads in 

 all directions. 



It prefers 40- to 80-year-old woods. The foliage is at first 

 only skeletonised, but after August the leaves are almost 

 entirely eaten and fall to the ground in thousands after the 

 caterpillars have bitten through the petioles. 



In the case of the oak, the petioles and mid-ribs remain. 



The damage done consists in loss of increment, and reduc- 

 tion in the production of seed, as fewer flower-buds are 

 developed ; the quantity of beech-mast is much diminished, 

 and the nuts are often empty. 



This is highly prejudicial to beech forests under natural 

 reproduction. 



The insect prefers southerly or south-westerly aspects ; it is 

 very common in North Germany, France and Belgium 

 (Ardennes), being found at altitudes up to 1,300 feet above 

 sea-level. It is tolerably common in Great Britain, but is 

 seldom destructive, except in hop-gardens. 



In 1892, the larvae of the pale tussock moth appeared on 

 about 2i acres of forest in the Grand Duchy of Luxem- 

 bourg, and by October 82 acres were leafless. By the end 

 of 1893, 5,000 acres of beech - wood were devastated, 

 and the caterpillars were so numerous as to impede 

 locomotives on the narrow-gauge railway. Owing to the 

 increase of parasites and diseases, the epidemic stopped in 

 June, 1894. 



il. Proteciivc Rules. 



i. Ash, sycamore and conifers should be grown in beech- 

 woods. 



ii. Protection of enemies — crows, jackdaws, cuckoos, 

 thrushes, finches, titmice, etc. Ground-beetles and ichneu- 

 mon-wasps are very efficacious, and a spider {Epcira, sp.) has 

 been observed to be extremely destructive to the insect. A 

 fungoid disease due to Isaria farinosa, Fries, with its higher 

 form, ConUceps militaris, Link, is also common. 



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