Free Access
| Issue |
Apidologie
Volume 31, Number 5, September-October 2000
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|---|---|---|
| Page(s) | 559 - 566 | |
| DOI | https://doi.org/10.1051/apido:2000146 | |
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
(
Abstract:
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
e-mail: bienero@uni-hohenheim.de
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