PRESENZA E DIFFUSIONE DI VARROA NEGLI ALVEARI DELLA CAMPANIA

Mites in the genus Varroa are obligate ectoparasites of honey bee populations worldwide. Recent evidence from morphological, geographical, and especially genetic variation has spurred an important revision of Varroa taxonomy. Specifically, mitochondrial DNA (mtDNA) evidence suggests that the main mite pest on western honey bees (Apis mellifera) is not Varroa jacobsoni, as first described, but a distinct species now named Varroa destructor. Genetic markers also have been used to support a taxonomic basis for regional differences in how Varroa mites impact honey bees. Recent morphometric and molecular studies confirmed the presence of the species V. destructor also in the apiaries of the Campania region of southern Italy. In the three-year period 2001-2003 a survey was conducted in 118 municipalities of the five provinces of the Campania region in order to add data to the limited epidemiological information available regarding Varroa destructor in this zone. The level of infestation by the mite was assessed on a total of 521 apiaries (241 apiaries were inspected on 2001, 154 on 2002, and 126 on 2003). In each apiary, 100 comb cells were examined and in each province the level of infestation was calculated using the following formula: (number of Varroa specimens/number of open comb cells) x 100. In order to display the level of infestation, Geographical Information Systems were used in order to draw parasitological maps