Anonymous, N/A, & Mediterranean Plant Protection Organisation., 2004c Citrus.. Bulletin OEPP 34(1): 43-56.
Notes: The principal citrus pests considered include armoured scales. Due to their great reproductive capacity, survival ability, and the difficulty of insecticide control, armoured scale insects (Diaspididae) are highly destructive pests of citrus. Apart from the newly hatched larvae and the adults which are mobile, all other stages are sessile, feeding on shoots, leaves or fruits. Sap sucking results in direct damage in the form of defoliation. Indirect damage includes depreciation of fruits, due to reduced size, green spots on the mature fruit at places where the scales were fixed, remains of scales. Aonidiella aurantii, Aspidiotus nerii and Lepidosaphes beckii are discussed in some detail. Among soft scales (Coccidae), the black scale Saissetia oleae is the most damaging, while the citrus brown soft scale Coccus hesperidum only causes occasional problems. Direct damage is caused by feeding which restricts the flow of assimilates to the fruits. The scales also secrete honeydew, on which sooty mould develops, reducing the vigour of the tree, causing defoliation, and suppressing flowering and fruiting on affected trees. S. oleae overwinters as larvae. Under Mediterranean conditions, there are two generations per year but this varies with climatic conditions. Other species discussed are Pseudococcus citri, Icerya purchasi and Unaspis yanonensis.