Nuove prospettive di previsione e di controllo delle infestazioni e del danno diLymantria dispar(L.) in Sardegna

In Sardinia (Italy) gypsy moth population density has been regularly evaluated through a monitoring network over thirty years based on egg masses counting at permanent sites. This activity allows to identify annually areas with the highest infestation density in order to define sites to be subjected to phytosanitary treatments.To give an indication on the potential use of different microbiological products two years of efficacy trials with different Bacillus thuringiensis serovar kurstaki formulations were carried out in period 2012-2013. Tested formulations proved to be as effective as the reference products Foray 48B and Delfin in controllingL. disparpopulations.Historical series data on gypsy moth over-year-density were analyzed following two different study approaches. The first was based on a generalized linear model adopted to evaluate the statistical significance of the relationship between percentage of occupied sites and presence of damage. The results confirmed the validity of this method for an easier identification of forest areas exposed to damage in progradiation phase. In the second case, the use of incidence function model and other statistical approaches were investigated. Although the complexity in modellingL. dispardynamics, results were promising for their use in defining the specific metapopulation dynamics pattern at forest district level.