86 [ DISEASES OF CITRUS TREES 



white threads or filaments along its sides. The larva is 

 of a paler colour. The male insect is a tiny two-winged 

 fly, which is occasionally seen hovering among the 

 lemon trees late in summer. The female constructs a 

 mass of cottony filaments of wax where to lay its eggs. 

 When the young are hatched they may be seen straggling 

 out of this mass of filaments and dispersing upon the 

 twigs and leaves. They seek the undersurface of the 

 leaves along the midrib, the axillae of the leaves and 

 the persistent calyx of the fruit. This insect is common 

 on young lemon trees, but is comparatively rare on 

 the orange, it is very injurious to Citrus groves in 

 Southern Europe, Sicily and North America, but it 

 cannot be described as very destructive to our groves 

 where the many enemies which prey upon it have 

 prevented it from increasing to a dangerous extent, 

 though this may not be a complete explanation for its 

 want of activity. The mealy bug is very common upon 

 the Leguminosae, and towards the close of summer 

 large masses of mealy bugs thickly covered with their 

 cottony web, may be seen clinging to the stem and 

 branches of Erythrina Corallodendron and other trees of 

 the same order, as well as on Euonymus, Ipomaea etc. 



leery a Purchasi Maskell, known as the Cottony- 

 cushioned Scale, or the Fluted Scale insect, is another 

 dangerous pest of the Citrus grove. Its native land is 

 Southern Australia and New Zealand, and its original 

 host seems to have been the Acacias and Wattles very 

 common in Australia. From Australia the insect passed 

 to California in 1875, attacking all fruit trees, particularly 

 Citrus trees. Now it is established in most temperate 

 regions of N. America and Europe, as well as in South 

 Africa. In 1896 it was introduced in the province of 

 Lisbon, Portugal, and soon afterwards it found its way 

 to Sicily and Portici, Naples. In 1907 the fluted scale 

 was imported from Sicily to Malta, on some ornamental 

 plants, and made its first appearance in certain gardens at 



