1. INRA, UR 406 Abeilles et Environnement, Avignon Cedex 9 84914, France
2. Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
3. 29, Avenue des Lierres, 84000 Avignon, France
4. Honeybee Research Institute, Jiangxi Agricultural University, Nanchang 330045, Jiangxi, People's Republic of China
5. I.R.B.I., UMR 7261 CNRS-Université François-Rabelais, UFR Sciences et Techniques, Tours 37200, France