Sentence:  The staminate willow catkins , then , provide their visitors with both nectar and pollen ; a marvelous arrangement , for it provides exactly what the <WSD>bee</WSD> queens need to make their beebread , a combination of honey and pollen with which the young of all species are fed . 
Meaning of the word marked with <WSD> tags:  any of numerous hairy-bodied insects including social and solitary species