I

ANNO 2 Numero 1
Vincenzo Palmeri [1], Orlando Campolo [1], Pompeo Suma [2]

Effectiveness of treatments with oxalic acid against Varroa destructor in free brood colonies in Mediterranean areas

[1] Dip. Agrochimica e Agrobiologia, Università degli Studi "Mediterranea", Reggio Calabria (Italy).
[2] Dip. Scienze e Tecnologie Fitosanitarie, Università degli studi di Catania (Italy).

Contact: vpalmeri@unirc.it

We report the results of two trials (1998-2000) conduct in Calabria for the control, in families without brooded cells, of Varroa destructor Anderson & Trueman through the oxalic acid employment. The tests have been realized on a total of 30 families of Apis mellifera L. placed in beehives of the type Dadant Blatt, equipped with one trap "Undebasket-Accorti" for the appraisal of mortality of the bees. Solution in oxalic acid water with saccharose is intentional to inquire the effectiveness of one treatment in the first year and replied a second one it turns the following year, always maintaining the same concentration. For the calculation of effectiveness of the treatment have been adopt, like reference parameters, the effectiveness percentage (E%) and the degree of action (GA) according to Henderson e Tilton (1955). In 1998 medium effectiveness (E%) assessed in the treated families, has been of 71,63% ± 15,71; the medium effectiveness obtained using the degree of action (GA) has been of 61,37% ± 21,20. In the second year have been recorded values of 91,33% ± 7,77 and 89,72% ± 9,22, respectively for the effectiveness (E%) and the degree of action (GA). The results obtained showed as, in Southern Italy, the oxalic acid cannot use like only remedy against V. destructor, although, the tests realized in the second year with a double treatment, leave to catch a glimpse perspectives of sure interest for the treatment of swarms of new formation or like solution pad between one productive campaign and the other.