Sealing up and non-removal of diseased and Varroa jacobsoni infested dronebrood cells is part of the hygienic behaviour in Apis cerana

The occurrence of drone brood cells with a closed pore in the conical cocoo n cap of Apis cerana was investigated in the Philippines and in Nepal. Clos ed pores in A. cerana drone cell caps result from nurse bees that fill in w ax material from outside until the pore is plugged, as SEM pictures and a p reliminary experiment revealed. All these closed cells contained dead brood that had been killed either by European foulbrood or by Thai sacbrood viru s. In Nepal, some dead drone pupae were found infested with Varroa jacobson i that also had a sealed pore in the cocoon cap. The results of this study demonstrate that sealing up and non-removal of diseased and V. jacobsoni in fested drone brood cells can be considered as part of the hygienic behaviou r of A. cerana honey bees.