Abstract:

Bumble bees and honey bees are important pollinators, but bumble bees are more efficient than honey bees for pollinating fruits and vegetables in greenhouses, which is mainly due to the different activity patterns in pollination between bumble bees and honey bees.The behaviour and activity patterns of Bombus lucorum and Apis mellifera for pollinating strawberry in greenhouse were comparatively studied. The results showed that their behaviour on the flowers was quite similar, but activity patterns were different. B. lucorum visited flowers at 8:00-8:05 earlier than A. mellifera at 9:25-9:40, and ended at 15:55-16:05 later than A. mellifera at 15:20-15:30 B. lucorum began visiting flowers at lower temperature （12-13℃） than A. mellifera did （>15℃）; moreover A. mellifera did not visit flowers in the early morning or cloudy day. The diurnal activity time of individual B. lucorum （271.43±4.48 s）was significantly longer than that of A. mellifera （180.00±2.64 s）. The foraging time of B. lucorum was 105.71±1.16 s,  significantly longer than that of A. mellifera (76.43±3.83 s). B. lucorum spent 3.81±0.42 s on shuttling between flowers, significantly shorter than that of A. mellifera (6.0±0.48) s. B. lucorum visited more flowers per minute （8.44±0.44） than A. mellifera did （2.38±0.15）. A. mellifera bees were not particularly selective between strawberry flower with different ages, and they visited 34% young flowers per day. In contrast, B. lucorum strongly selected young flowers， and up to 55% of the flowers visited were young （P<0.05）; B. lucorum visited 75% young flowers at 9:00-12:00, whereas A. mellifera visited 31% young flowers at the same time. B. lucorum bees moved around more than did A. mellifera, and they frequently visited only one or two flowers in a patch and then flew some distance along the rows or between rows, with a mean “row length" per visit sequence of 5.2 m. In contrast, the mean “row length" for all A. mellifera visit sequences was just 1.1 m. It was so concluded that B. lucorum bumble bees are more efficient pollinators for greenhouse strawberry than A. mellifera honey bees.

Key words: Bumble bee, honey bee, greenhouse, strawberry, pollination behaviour, activity pattern