Free access
Volume 30, Number 6, 1999
Page(s) 491 - 503
Apidologie 30 (1999) 491-503
DOI: 10.1051/apido:19990604

Development of Varroa jacobsoni in colonies of Apis mellifera iberica in a Mediterranean climate

Manuela R. Branco, Neil A.C. Kidd and Robert S. Pickard

School of Pure and Applied Biology, University of Wales, PO Box 915 Cardiff CF1 3TL, Wales, UK

Abstract - Studies on Varroa jacobsoni population dynamics were conducted on 32 full-sized honeybee colonies of the Iberian bee race. The V. jacobsoni population growth followed an exponential model until it reached a collapse phase. In the experimental conditions this happened about 8 months to 1 year after chemical treatment. On average, the weekly intrinsic mite growth rates were very high, the yearly increases in mite population were 209 232-, 5 436-, 942- (with drone baiting) and 3 036-fold. A modelling approach was developed to describe the mite intrinsic growth rate regarding a) an overall range, b) only growth phenomena or c) only decay phenomena. The probability of each mite finding a free larva on which to reproduce, the occurrence of mite immigration, and the mite death rate were the most significant variables to explain the mite intrinsic growth rate during the growth phase. The model had a good fit, R2 = 0.905, and good predictive performances, R2 Prediction = 0.896. © Inra/DIB/AGIB/Elscvier, Paris

Key words: Varroa jacobsoni / Apis mellifera iberica / population growth / Mediterranean climate / statistical modelling