Diurnal patterns of bee activity, flowering, and nectar reward per flower in tetraploid red clover

Abstract

Patterns in the activity of insect visitors to ‘Grasslands Pawera’ red clover were investigated in two dawn-to-dusk studies. Long-tongued bumblebees, mainly B. hortorum, were the most abundant positive flower visitors on both days. B. Terrestris was a frequent visitor but usually visited negatively, robbing nectar through holes bitten at the base of flowers. Honey-bees were less frequent visitors, despite the proximity of hives, and most robbed. Bumble-bees foraged for a longer period each day than honey-bees and visited flowers most frequently in the evening. A peak in the number of newly opened flowers occurred around midday on 7 February and the amount of sugar per red clover flower was higher in the afternoon when investigated in detail on 18 January. Foragers from a boxed B. hortorum colony nearly all worked the red clover. © 1992 Taylor & Francis Group, LLC.