Ontogenesis of the mite Varroa jacobsoni Oud. in drone brood of the honeybee Apis mellifera L. under natural conditions

A study carried out during the summer of 1994, in southern England, investigated the developmental times and mortality ofVarroa jacobsoni inApis mellifera drone cells. The position and time of capping of 2671 naturally infested drone cells were recorded. Six hours after the cell was capped, 90% of the mites were free from the brood food to start feeding on the developing drone. The developmental time of the mite's first three female offspring (133±3 h) and the male offspring (150 h) and the intervals between egg laying (20–32 h) were similar to those found in worker cells. However, the mortality of the offspring was much lower in drone cells than worker cells. The mode numbers of eggs laid were six and five in drone and worker cells, respectively. All offspring had ample time to develop fully in drone cells with the sixth offspring reaching maturity approximately 1 day before the drone bee emerged. Normal mites (those which lay five or six viable eggs) produced on average four female adult offspring but since only around approximately 55% of the mite population produced viable offspring the mean number of viable adult female offspring per total number of mother mites was 2 to 2.2 in drone cells.