Exotic Scale Insects (Coccoidea) on Ornamental Plants in Italy: a Never-Ending Story

The introduction of ornamental plants into Italy for commercial and hobby purposes has provided scaleinsects with many chances of dispersion. Coccoidea often go unnoticed at border controls due to theircryptic lifestyle. Moreover, many of the introduced alien species become acclimatized outdoors, possiblydue to the effects of urban pollution and global warming. The authors attempt to analyse this phenomenonand report on the records of new alien species in Italy, starting from the end of the Second World War. Inthe period 1945-1995, an average of 0.64 new introduced alien species were reported per year, whereas anaverage of 0.7/year were introduced between 1995 and 2005 and 1.25/year since 2005. About fifty alienspecies have been recorded so far in Italy, of which about 50% are presently acclimatized on ornamentals.The increase in alien species introduction is probably due to: the ever easier and faster transport and dispatchof plants in a globalized world trade; the free movement of goods within the European Union; andthe weakness of the National Plant Protection Organization (NPPO) monitoring. Moreover the effect ofglobal warming may have played an important role, directly enhancing the survival and development ofthe insects in their new environment. The authors comment and discuss the more invasive species, namelyCeroplastes japonicus Green, C. ceriferus Fabricius, Protopulvinaria pyriformis (Cockerell), Phenacoccusmadeirensis Green, Phenacoccus peruvianus Granara de Willink, Phenacoccus defectus Ferris, Chrysomphalusaonidum L. and Aulacaspis tubercularis Newstead.