Mussel Scale. 



509 



In a short time they fix themselves to the plant by their short 

 proboscis and draw away the sap ; the scale then commences to 

 form by the excretion of a few waxy threads and gradually 

 grows to the form shown in Fig. a. During this period the 

 larva loses its legs and becomes converted into a fleshy legless 

 creature ; the female remains feeding beneath the scale and is 



Fig. d, Piece of branch infested with Mussel Scale. 



provided with a long flexible proboscis, which is inserted into 

 the tissues of the plant. Towards the end of the summer she 

 deposits her eggs and dies, her shrivelled skin remaining 

 beneath the scale. 



If the larva is going to become a male, not only is a different 

 scale produced (most often upon the leaves) but a totally 

 different mature insect. The male undergoes a kind of pupal 

 stage and escapes from the scale as a small winged insect. The 

 males are very rare, most of the females reproducing asexually. 

 A single brood normally exists in this country. 



Scales have many natural enemies, but this species and those 

 that attack the currant in this country are not materially 

 lessened by them. Amongst the natural enemies birds alone do 

 any good. The Paridae or tits and a few other birds, such as 

 the tree-creeper and wryneck, feed upon this scale. Lady- 



