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

Abstract: The armoured scale Chrysomphalus aonidum (L.) was detected for the first time inthe region Calabria in 2006 on ornamental bitter orange. Studies on its biology were initiateddue to the importance of the damages caused by this insect in many citrus growing areas of theworld. The distribution and biology of C. aonidum were investigated in 2008-2009, in order toacquire essential knowledge for pest control and to monitor its dispersion in commercial citrusorchards. Moreover the composition and the role of its natural enemies were studied. Theobservations carried out showed that the scale is able to complete 4 generations per year (thefirst one in May, followed by a second one at the end of July, a third at the end of September anda final one in the first ten days of November). The species mainly overwinters as virgin female.Males overwinter as pupa and pre-pupa. The observations on the scale natural enemies complexrevealed the sole presence of indigenous coccinellid predators, among which the most commonappeared to be Chilocorus bipustulatus L. The survey on the C. aonidum distribution showedthat the species has spread and is now present also in commercial citrus orchards.