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Volume 31, Number 5, September-October 2000
Page(s) 559 - 566
DOI: 10.1051/apido:2000146

Apidologie 31 (2000) 559-566

Toluidine blue staining as a rapid measure for initiation of oocyte growth and fertility in Varroa jacobsoni Oud

Claudia Garridoa - Peter Rosenkranza - Matthias Stürmera,b - Ralph Rübsamc - Jürgen Büningc

aUniversität Hohenheim, Landesanstalt für Bienenkunde, August-von-Hartmann-Strasse 13, 70599 Stuttgart, Germany
bBayerische Landesanstalt für Bienenzucht, Burgbergstrasse 70, 91054 Erlangen, Germany
cUniversität Erlangen-Nürnberg, Institut für Zoologie I, 91054 Erlangen, Germany

(Received 17 February 2000; revised 21 April 2000; accepted 19 May 2000)


A whole mount method was used to determine the moment of activation of oocyte growth in Varroa jacobsoni females. Ovaries of the mites were dissected and stained with toluidine blue. The coloration of the terminal oocyte indicates the uptake of euplasmatic and/or yolk material and, therefore, the initiation of the reproductive phase. In phoretic mites from adult bees, no staining of the ovary could be detected. V. jacobsoni females artificially introduced into freshly capped brood cells and removed for dissection 6 h later already showed clear blue staining of the terminal oocyte. The ovaries of V. jacobsoni females introduced 14 h after capping of the brood cell, however, remained uncolored after incubation in toluidine blue. We conclude that, in phoretic mites, oogenesis is arrested at a previtellogenic phase. Immediately after invasion of the brood cell, reproduction is activated by an as yet unknown host factor. This factor is present in freshly capped brood cells but not in brood cells 14 h after capping. Our new method offers new possibilities for the exact determination of oocyte growth and, therefore, for the study of V. jacobsoni fertility in different host and parasite populations.

Keywords: Varroa jacobsoni / host-parasite relationship / vitellogenesis / oogenesis / fertility / reproduction

Correspondence and reprints: Peter Rosenkranz

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