ABSTRACT
A survey on coccids infesting citrus-groves was made in Eastern Sicily and Ca labria during 1979-80. The most widely distributed species were: Planococcus citri (Risso), Coccus hesperidum L., Saissetia oleae (Oliv.), Ceroplastes nisci L., Parlatoria pergandei (Comst.), Aspidiotus nerii Bouche and Mytilococcus beckii (New.).
Other species collected in more restricted areas were: Pericerya purchasi (Mask.), Pseudococcus longispinus Targ., Coccus pseudomagnoliarum (Kuw.), Saissetia coffeae (Walk.), Ceroplastes sinensis D.G., Parlatoria ziziphus (Lucas), Mytilococcus gloverii (Pack.), Chrysomphalus dictyospermi (Morg.) and Aonidiella aurantii (Mask.).
On the basis of the infestation-rate, the most important species were: Pl. citri (Citrus mealybug), S. oleae (Black scale), C. rusci (Fig wax scale), P. pergandei (Chaff scale) and M. beckii (Purple scale); with regard to the lemon-trees, A. nerii (Oleander scale) and A. aurantii (California red scale) are particularly injurious.
The most important scales arediscussed from the biological and ethological point of view, with particular emphasis on the biological control of Pl. citri by the entomophagous Scymnus (Nephus) reunioni Fursch, Cryptolaemus montrouzieri Muls.(Col. Coccinellidae) and Leptomastidea abnormis (Grit.), Anagyrus pseudococci (Grlt.), Leptomastix dactylopii (How.) (Hym. Encirtidae).
