Figure 3

Hygienic behavior of starting populations. A. HB of the Y1 colonies in Grand Forks, BC and at the Research Farm in Beaverlodge, Alberta, showed a wide range of HB values as determined by the proportion of cells that were uncapped and pupae were removed after 24 h (R24h) using the liquid nitrogen freeze-killed brood method. B. The five populations analysed in Beaverlodge, one originated in Saskatchewan (SK), two in California (CA1 and CA2), one in Chile (Ch) and one in Ontario (ON), also showed a wide range of HB.