Preliminary results on the spatio-temporal variability of glycaspis brimblecombei (Hemiptera Psyllidae) populations from a three-year monitoring program in sardinia (Italy)

The red gum lerp psyllid Glycaspis brimblecombei is an invasive insect species worldwide. Prolonged attacks by this psyllid may cause both direct and indirect damages to Eucalyptus trees, such as plant weakening, developmental reductions and phylloptosis, resulting in death within 2-3 years. After the first report in Campania (Italy) in 2010 on Eucalyptus camaldulensis trees, it quickly spread to all surrounding central-southern regions of Italy. In Sardinia, G. brimblecombei was first recorded in 2011, and is currently found throughout the island. From 2013 to 2015 a monitoring program was carried out in 11 locations throughout Sardinia in order to estimate the density pattern of both its adults and preimaginal stages, as well as the general population trend of G. brimblecombei over the years. An analysis of G. brimblecombei population abundance showed an almost stable level of infestation over the years, and a seasonal pattern with a population peak in the summer. However, an earlier peak of population abundance was detected in 2015 compared to the previous years. A spatial heterogeneity of the level of infestation was observed throughout the island, highlighting the potential effects of environmental conditions in regulating the populations of both G. brimblecombei and its natural enemies.