78 [ DISEASES OF CITRUS TREES 



which is under it, the scale itself being almost translu- 

 cent. When this insect is very numerous its scales 

 coalesce and may be separated in large flakes sticking 

 together. It is probably a mere variety of the preceding. 



Aspidiot^ls Ficus, Ashmead, or Chrysomphalus 

 Aonidium L., the red scale of Florida, is also a 

 circular scale of a reddish brown colour and some- 

 what larger than the preceding. It is found in 

 Cuba and other islands of the West Indies, and also 

 in some States of North America especially in Florida. 

 So far it has not been noticed in Malta. It attacks 

 not only Citrus trees but also many fruit trees, orna- 

 mental trees and shrubs. Young trees and shrubs are 

 often killed by it, but adult trees do not seem to suffer 

 much, beyond having the fruit and the leaves disfigured. 



Aspidiotus Aurantii Maskell, the red scale of 

 California, is of the same size and shape as Aspidiotus 

 Ficus. The scale is translucent. The reniform body 

 of the insect which gives its colour to the scale which 

 covers it, is yellowish to reddish brown, so that the outer 

 | of the scale appear as a broken ring of reddish brown 

 enclosing a white dot, which represents the mass of 

 waxy filaments that covered the insect soon after it 

 ceased to be a larva. The native land of this species 

 is Southern Australia and New Zealand. It has not 

 yet found its way to these Islands. In all species of 

 Aspidiotus the scale of the male is much smaller, nearly 

 elliptical in shape and of a lighter colour. After the 

 third moult the male insect leaves the scale in the 

 shape of a winged fly. 



Chrysomphalus dictyospermi Maskell, a red scale 

 similar to Aspidiotus Ficus has been introduced in Malta 

 from Catania (Sicily), in 1911, on rose-bushes and other 

 ornamental plants, and in three or four years it has 

 spread with marvellous rapidity to most groves and gar- 

 dens in the Island. The scale is round as in other 



