Leaflet No. 140. 



BOARD OF AGRICULTURE AND FISHERIES. 



The Felted Beech Coccus {Cryptococcus fagi). 

 Distribution. 



This insect confines its attacks exclusively to the beech 

 (Fagus sylvatica), and is one of the most destructivelpests 

 against which the arboriculturist has to contend. It ''is 

 widely distributed throughout England, and has occurred in 

 many parts of Scotland. It is common in the counties of 

 Flint and Denbigh in North Wales ; while in Ireland it has, 

 so far, been recorded from one locality only. Its attacks are 

 often restricted to a comparatively small area, or even to 

 single isolated trees, this being especially noticeable where 

 the tree-trunks are sheltered from the prevailing winds. 



Signs of Infestation. 



Owing to the whiteness of the felted covering with which 

 the female protects its body, and also to its exposed position 

 upon the trunks and main branches of the trees, the beech 

 coccus is at all times a conspicuous species, and more 

 especially so when the white secretionary coverings unite 

 and almost completely cover the bark of the tree. 



Young and old trees are alike attacked ; and the insects 

 usually confine themselves to the main trunk and larger 

 branches ; but the smaller branches, especially those of young 

 trees, are sometimes infected to a serious extent. Where 

 the infected trees are growing in exposed situations the 

 insects almost invariably select the sheltered side of the 

 tree. Many badly infected trees which have been under 

 close observation for the last sixteen years are still appar- 

 ently vigorous and healthy, while others have been totally 

 destroyed. The first sign of decay is usually seen in the 

 foliage, which becomes discoloured and sparse or thin, 

 accompanied by the death of the smaller branches ; this is 

 followed by the death of the larger branches and, finally, 

 the tree trunk ; while the bark peels off from the branches 

 and falls away. Whether the work of destruction is aided 

 by the joint action of a bacterial or fungoid disease is not at 

 present known, but it is probable that such is the case, 

 otherwise it is difficult to understand how so many badly 

 infected trees withstand the attacks of the insects for such 

 long periods without showing any evident signs of decay. 



Description and Life-History. 



The beech coccus belongs to the generally destructive 

 family of Scale insects (COCCID^:). The adult female 

 is of a lemon-yellow colour, and measures about one 

 twenty-fifth of an inch in length. It is both wingless 

 and legless ; is somewhat hemispherical in shape, being 



25000 WtP 2130 11/05 D&S 8 23079r 



