Ineffectiveness of Apistan® treatment against the mite Varroa jacobsoni Oud in several districts of Lombardy (Italy)M. Lodesania, M. Colombob and M. Spreaficoc
a Istituto Nazionale di Apicoltura, via S Giacomo, 9, 40126 Bologna, Italy
b Istituto di Entomologia agraria, Università degli Studi, via Celoria, 2, 20133 Milan, Italy
c Laboratorio Apistico, Unione Regionale tra le Associazioni dei Produttori Apistici della Lombardia, via Celoria, 2, 20133 Milan, Italy
Abstract - The effectiveness of Apistan® (Sandoz) was tested in 8 apiaries (78 colonies) in some districts of Lombardy (north Italy) during 1993. The strips were left for 22 d in colonies in which the queens were caged inside the hives. On the 24th day, a treatment with 5 ml/comb of Perizin® was given. The fallen mites were recorded every 8 d during Apistan® treatment and 2 d after Perizin®. The treatment's average effectiveness varied greatly from apiary to apiary (min 4%, max 89.5%). In Lombardy, where quite a high mortality of colonies (caused by varroosis) was reported by some beekeepers during autumn 1992, the average effectiveness of the treatment with Apistan® was 44.5%. The results indicate different levels of resistance of Varroa jacobsoni to fluvalinate.
Key words: Apis mellifera / Varroa jacobsoni / fluvalinate / effectiveness / resistance