A study made by Mia Davidsson in 1992 at the Swedish University of Agricultural Sciences as an examination paper.

When the mite can only reproduce in sealed brood cells, there is a hyphotesis that we can reduce the number of mites with a shorter capping stage. When smaller bees, (Apis cerana and Apis mellifera capensis), are more resistant to the mite, this research aim to find out if it is possible to get shorter capping stage with smaller cells in European bee colonies.

Three different foundations were used, 640, 770, and 900 cells/ sq.d123. The foundations were introduced in three different colonies at the University, and the postcapping stage and the weight of the bees were compared.

At Gotland, the place in Sweden with most infested colonies, the foundations were introduced into five colonies using the trapping comb method. Then cells were opened and inspected for Varroa mites in each comb. The offspring of the mother mites were divided in different groups and compared between the different cell sizes.

The distribution between reproducing and non reproducing female Varroa mites in the different types of wax

The distribution of different types of offspring.

Distrubution of offspring

640 cells/sq.dm

770 cells/sq.dm

900 cells/sq.dm

Total

Both female and male

73

89

85

247

Only female

27

11

32

70

Only male

10

17

17

44

Only protonymph

22

23

8

53

No offspring

18

10

8

36

Total

150

150

150

450

No difference could be found in postcapping stages between the cell sizes. There was a tendency to smaller bees in smaller cells. Comparision of the reproduction of the mites in different cell sizes showed no significant differences if the material was divided into two groups, fertile and non fertile mother mites. There were significant diffrerences between cell sizes in offspring composition but the result do not indicate that the reproduction of mites was substantially influenced by cell size on worker bee brood.