Data consists mostly of strepsipterans-parasitized and non-strepsipteran-parasitized bees flower-visiting behaviour on Hydrangea serrata inflorescences.  We analysed the recorded video by comparing time spent on an inflorescence between parasitized and unparasitized bees, Lasioglossum apristum and by comparing each bee's behaviour on the flower. We defined four flower-visiting behavioural units: (1) walking on flowers, (2) touching antennae and mouth to the flower, (3) collecting pollen, and (4) bending the abdomen downward and pressing the dorsal abdomen against the flower. We also observed whether the mouth of the bee touched a pistil or its base, where nectar might be found. Among these four behavioural units, unit 1 is incompatible with the other behavioural units, whereas units 2 and 3 and units 2 and 4 are compatible pairs and often occurred simultaneously. Units 3 and 4 never occur in the same bee. The behavioural repertoires of parasitized and unparasitized bees and the time spent on each behavioural unit were determined from video frames. We measured the cumulative time spent on each behavioural unit by each flower-visiting bee and then compared how parasitized and unparasitized bees allocated their flower-visiting time to the behaviour units.