Apidologie 28 (1997) 427-437
DOI: 10.1051/apido:19970609

Damaged Varroa mites in the debris of honey bee (Apis mellifera L) colonies with and without hatching brood

P. Rosenkranz^{a, b}, I. Fries^c, O. Boecking^d and M. Stürmer<sup>a, b

a</sup>  Bayerische Landesanstalt für Bienenzucht, Burgbergstrasse 70, D-91054 Erlangen, Germany
^b  Universität Hohenheim, Landesanstalt für Bienenkunde, August-von-Hartmann-Strasse 13, D-70593 Stuttgart, Germany
^c  Department of Entomology, Swedish University of Agricultural Sciences, S-75007 Uppsala, Sweden
^d  Institut für Landwirtschaftliche Zoologie und Bienenkunde, Abteilung Bienenkunde, Melbweg 42, D-53127 Bonn, Germany

Abstract - The proportion of damaged Varroa mites within the debris of honey bee colonies is discussed as a possible tolerance factor of the host. We investigated the rate of damaged Varroa females in honey bee colonies with and without hatching brood. Additionally, in some colonies sealed brood combs were treated by the use of heat or formic acid to kill the mites within the brood cells to quantify the behaviour of the bees towards dead mites. In 17 experimental honey bee colonies (Apis mellifera) at two different study sites, the debris was checked at 12-h intervals. Nearly 5 000 mites were individually analyzed for three different types of damages. The percentage of damaged mites varied on average from 44 to 63% depending on experimental conditions. No significant differences in the damage rates of 'phoretic mites' and 'brood mites' could be found. Dead mites from the treated brood combs were damaged to a slightly lesser extent. The significance of these results for the use of the parameter 'damaged mites' in selection programs is discussed.

Key words: Varroa jacobsoni / Apis mellifera / damaged mites / resistance