The development of pollination inserts

The objective of the project was to develop pollination insert devices that might be fitted to honeybee colonies to increase the level of in-hive pollen transfer, and in so doing increase the amount and diversity of pollen on departing foragers, and without disrupting foraging, resulting in improved pollination, fruit set and fruit quality.

Initial experiments in 2004 confirmed previous reports (Hatjina 1998; Hatjina et al 1998; Hatjina et al 1999) that the use of felt in-hive pollen transfer devices is the most effective (in comparison with woollen fabric, sponge, hard bristles and soft bristles) in increasing pollen load on departing foragers. The use of hive-entrances devices with felt on both sides and gap of 8mm was found to increase pollen abundance by as much as 150% compared to control colonies. However, the application of the standard hive-entrance device reduced foraging rates by between 30% and 1000%. This reduction in foraging rate negated any positive benefit that might have accrued due increased pollen diversity being present on departing foragers.

The reduction in foraging rates was largely alleviated by the development of a new in-hive device that rests below the colony. This device requires returning and departing foragers to climb over a series of three ramps or hurdles each time they enter or depart the hive. At the top of each ramp the thorax of the bee will come into contact with the felt, thus increasing the in-hive pollen transfer. This new design, by spreading out the congestion points, was found to reduce foraging rates very little, if at all, and appears not to be an irritation to hive bees.

The effectiveness of this new design in increasing in-hive pollen transfer (both in abundance and diversity) and the impact of this on improved fruit set was tested in the 2005/2006 season under field conditions, using Abate Fetal pear orchards. None of fruit size, number of seeds in fruit or fruit set was found to be increased by the pollen inserts. Rather, there was a small decrease in all categories, approximately equivalent to the small decrease in foragers that would be expected in honeybee colonies having the pollination insert devices. Additional changes are planned for the pollination devices in a further attempt to make them effective in improving fruit quality and production.