Response of Apis cerana Fabr towards brood infested with Varroa jacobsoni Oud and infestation rate of colonies in ThailandW. Ratha and W. Drescherb
a Institut für Landwirtschaftliche Zoologie und Bienenkunde der Universität Melbweg 42. 5300 Bonn 1, FRG
b Ministry of Agriculture and Cooperatives Department of Agricultural Extension, Beekeeping Subdivision; Regional Agricultural Extension Office, Arruk Rd Soi 5, Amphoe Muang, 50000 Chiang Mai, Thailand
Abstract - Apis cerana F, colonies responded with effective removal behavior towards sealed worker brood that was artificially infested with vital of dead Varroa jacobsoni Oud. The bees removed artificially infested drone brood to a very low extent. A cerana workers showed a differential hygienic behavior towards freeze killed sealed brood, consisting of fast removal of dead worker and slow removal of dead drone brood. The V jacobsoni populations infesting A cerana colonies in South Thailand were determined by acaricide treatment. A maximum infestation with 798 mites was ascertained.
Key words: Apis cerana / Varroa-resistance / hygienic behavior / natural infestation / Thailand