756 



The Felted Beech Coccus. [march, 



county of Cheshire, and has proved a troublesome and destructive 

 pest. 



Its distribution outside the British Isles has not been very 

 generally observed, but it is common in some parts of Germany, 

 and has been met with plentifully in Bohemia. 



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, it is at all times 

 a conspicuous species, and more especially so when the white 

 secretionary coverings unite and form one homogeneous mass, 

 thereby almost completely covering 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 apparently 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 (Fig. 5) 

 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 it is that so many badly infected trees 

 withstand the attacks of the insects for such long periods, as they 

 undoubtedly do, without showing any evident signs of decay. 



Description and Life-History. — The beech coccus belongs to 

 the generally destructive family of Scale insects (COCCID^E). 

 The adult female (Fig. 2) is of a lemon-yellow colour, and 

 measures about one twenty-fifth part of an inch in length. It is 

 both wingless and legless ; is somewhat hemispherical in shape, 

 being flattish beneath and highly convex above ; to the naked eye 

 or under low magnifying power it appears like a small yellow egg. 

 The mouth organs are placed on the underside of the body, 

 and are composed chiefly of three hair-like appendages which 



