Toluidine blue staining as a rapid measure for initiation of oocyte growth and fertility in Varroa jacobsoni Oud Claudia Garrido, Peter Rosenkranz, Matthias Stürmer, Ralph Rübsam and Jürgen Büning Apidologie, 31 5 (2000) 559-566 DOI: 10.1051/apido:2000146