-Workers of open-nesting honey bee species form a bee curtain to cover the comb and protect it against adverse environmental conditions and predators. We studied different aspects of structural and temporal dynamics of the bee curtain in Apis florea . First, in the course of daily observations, we discovered massed flight activity (MFA) of A. florea colonies similar to that previously described for A. dorsata . The MFAs started with the opening of gaps in the curtain and appearance of chains of bees shortly before the massed take off. Second, monitoring the worker movement patterns in the outer layer indicated a constant turnover of bees in the curtain. Finally, introduction of marked 1-day-old workers showed that workers joined the curtain at a very young age. First flight activity appeared around day 20, but the majority of workers started to fly after day 47, which is twice the age at which A. mellifera workers start to forage.Apis florea / open-nesting / bee curtain / massed-flight activity

Studies on behavioral maturation and division of labor in open-nesting honey bee species are scarce as the bee curtain inhibits direct examination of intranidal behaviors. We observed and studied nursing behavior in Apis florea by attaching a foreign comb with open brood to a host colony. Several of the workers that explored the attached comb visited the cells with brood more often and spent more time in cells compared to empty cells. Workers seen inspecting and feeding the brood had well-developed hypopharyngeal glands compared to foragers of their own colony indicating that they are nurses performing nursing behavior. Further, introducing marked 1-day-old workers into the host colony and repeatedly attaching combs with open brood allowed us to estimate the age range of nursing behavior. In our experiments, A. florea workers started to perform significant nursing behavior 8 days after eclosion and continued to show nursing behavior until the age of 28 days, the end of our observation period. Thus, nursing behavior in A. florea appears to be substantially extended relative to A. mellifera .