Small hive beetle (Aethina tumida) oviposition behaviour in sealed brood cells with notes on the removal of the cell contents by European honey bees (Apis mellifera)

Small hive beetles (Aethina tumida Murray) can lay eggs cryptically through the cappings of sealed bee brood cells. However, honey bees (Apis mellifera L.) can detect this activity and respond by removing cell cappings and contents (hygienic behaviour). We were interested in identifying conditions that regulate this syndrome of stimulus and response. Beetle oviposition rate (proportion of cells in which beetles perforate the capping and oviposit) into sealed brood cells was shown to be unaffected by a range of beetle densities created experimentally in caged sections of sealed brood. Oviposition rate was, however, increased when beetles had access to a sealed brood cell not only at the capping, but also along at least one side if the cell was next to an empty cell. Beetle oviposition rates into sealed brood cells were unaffected by the presence of Varroa destructor mites in the cell within a range of 1-4 mites per cell. The expression of hygienic behaviour toward beetle-perforated brood cells ranged from 10.6 77.2 % across colonies, but was unaffected by the colony strength parameters of bee population and cm brood.