Observations on the biology of Chrysomphalus aonidum (L) (Hemiptera: diaspididae) in Southern Italy and its natural enemies

The armoured scale Chrysomphalus aonidum (L.) was detected for the first time in the regionCalabria in 2006 on ornamental bitter orange. Studies on its biology were initiated due to the importanceof the damages caused by this insect in many citrus growing areas of the world. The distribution andbiology of C. aonidum were investigated in 2008-2009, in order to acquire essential knowledge for pestcontrol and to monitor its dispersion in commercial citrus orchards. Moreover the composition and therole of its natural enemies were studied. The observations carried out showed that the scale is able tocomplete 4 generations per year (the first one in May, followed by a second one at the end of July, a thirdat the end of September and a final one in the first ten days of November). The species mainly overwintersas virgin female. Males overwinter as pupa and pre-pupa. The observations on the scale natural enemies’complex revealed the sole presence of indigenous coccinellid predators, among which the most commonappeared to be Chilocorus bipustulatus L. The survey on the C. aonidum distribution showed that thespecies has spread and is now present also in commercial citrus orchards.