Trials involving four commercial apiaries testing various supplementary feeding strategies were conducted over the winter periods of 2003 and 2004. This research provided evidence of the vagrancies of supplementary feeding honeybees over the winter. It also provided a direction for future research in this area and a number of suitable options to consider.

Aims and Objectives
The objective for the 2003 trial was to provide evidence that supplementary feeding honeybee colonies will increase bee populations through a winter period with the aim to test supplementary feeding strategies to increase the colony population in each hive prior to the onset of almond bloom in mid August. This necessitated the provision of supplements during a winter period with the colonies exposed to the prevailing climatic winter conditions.

The objective for the 2004 trial was to maintain colony populations on a pollen deficient nectar flow using pollen supplement with the aim to test the effectiveness of various pollen supplements against a control, while colonies of bees were foraging on a pollen deficient nectar flow. The floral species chosen for this trial was winter flowering mugga ironbark (Eucalyptus sideroxylon).

Materials and Methods
Two commercial apiaries were utilised in the 2003 trial. All colonies were re-queened in early April. The initial measurement was taken in early June, with an interim measurement in mid August and the final measurement in late October. Treatments were sugar syrup, pollen supplement and a combination of both, compared to the control. Treatments were applied either every three or six weeks. Ten colonies from each apiary were allocated to each treatment. Initial and final measurements included total weight gain, frames covered in bees, area of brood, area of pollen, frames of honey, nosema levels of adult bees and the crude protein levels of pupae.

Similar to the 2003 trial, two commercial apiaries were selected for the 2004 trial. All colonies were re-queened in early March, initial measurements were taken in late April and the final measurements taken in late August. The measurement criterion was the same as in 2003.

Treatments were pollen, soyflour or a mix of soyflour (50%), pollen (25%) and yeast (25%), split into a feeding regime of every two or four weeks. These treatments were compared to a control. The apiaries were located on a mugga ironbark (Eucalyptus sideroxylon) nectar flow which does not provide pollen that is attractive to honeybees. Traditionally, this floral species is responsible for some excellent honey crops but managing the short fall of pollen has been a major management issue for beekeepers.

Results and Discussion
In the 2003 trial there were significant differences between the apiaries independent of the treatments, indicating strong climatic and floral reward variations between apiary locations.

The strongest response was observed when one apiary had access to a flowering canola crop after almond pollination, and the other apiary did not. In this case, the frames of bees per hive were not significantly different between apiaries although the area of brood was twice as large in the colonies that had access to canola and pear blossom, than the colonies that did not.

There was no significant difference in the crude protein levels of the pupae between treatments.

Also there was no significant trend from the August measurement across either apiary suggesting that any one treatment was superior to the control. In the October measurement, again there was no clear benefit by adopting any one of the feeding practices tested.

The five litres of sugar syrup and 500 gram pollen patty per application was, in many cases, excessive for the colonies’ ability to remove the supplements. These treatment volumes were applied irrespective of the size of the colony. Based on the data obtained from recording unused sugar syrup and pollen supplement, it is recommended that 50 grams of patty and 500 ml of syrup per frame of bees per month should be considered as a maximum quantity for mild winter conditions as experienced in western NSW and Victoria. Pollen supplements and sugar syrup should be provided to a colony on a volume or weight formula, based on the size of the population of the colony.

There was strong evidence that any benefit from the various supplements provided to the colonies was overridden by the adult bee disease Nosema apis. This disease is known to reduce the longevity of adult bees and thus suppresses population increase when nectar and pollen conditions are suitable for providing stimulus for a colony to expand its population. Also, the trial provided evidence that the provision of supplements to a colony during the winter period may have increased nosema levels in adult bees.

The results from the 2004 trial provided evidence that all three different preparations of supplementary feeding had some benefit with a ranking of pollen, then the soyflour/pollen/yeast mix and then soyflour last. Even so, the control colonies produced more honey in one apiary, thus the benefit was not uniform across both apiaries. There was a significant spread in the results for each treatment, suggesting that the responses from individual colonies can be considerable given the same set of circumstances.

Nosema disease was not a significant factor in 2004. The reasons for this were unclear, although the colonies were ‘interfered’ with less than in 2003 and hives were not dismantled to apply the treatments as was the case in 2003.

An attempt to measure the attractiveness of three sources of soyflour provided in bulk containers to foraging bees was not conclusive. The technique used to measure the feed left over in this trial was not satisfactory due to the feeding behaviour of bees, scratching the flour out of the containers.

There was a lack of replication in this experiment. Even so, observation suggests bees will favour one source of soyflour over another, particularly when exposed in a bulk feeder. Soyflour on its own as a supplement was far more attractive to bees within the bulk containers than when placed on trays under the lids of each bee hive.

Implications
Essentially, the 2003 trial failed to provide a strategy for apiarists to artificially increase populations of bees over the winter period. Even so, a significant result was achieved in providing reasons why this was not accomplished, and possible future research directions.

If colonies are required to be a certain size population in late winter or early spring, then management strategies must be implemented during the autumn period prior to winter. This will give sufficient time to expand the population of the colonies to the required size with little or no management activity to the colonies during the winter period. In the event of imminent starvation, sugar supplementation in the form of dry sugar rather than syrup may be preferable.

The 2004 winter trial was primarily aimed at trialling pollen-supplement, as nectar was not a limiting factor. While pollen on its own as a supplement was the most attractive substance, the cost benefit of the exercise to a beekeeper was questionable. This conclusion was based on honey yields and subsequent financial returns. There may be a benefit of providing pollen if colonies are to be maintained for pollination services particularly for the late winter and early spring period. Essentially this trial supports autumn preparation for a winter nectar flow, as a large percentage of the colonies in both apiaries declined in number of bees in winter even with pollen and nectar available.

Recommendations
Beekeepers should carefully consider the economics of supplementary feeding honeybees and provide controls in any future feeding strategies that they may adopt. Only by this approach of measuring production increase, compared against a control, will individual beekeeping managers become confident that supplementary feeding, under certain circumstances, is economically beneficial.

It is also recommended that future field research on supplements should include greater numbers of colonies per treatment or use package bees of known weight on empty combs.

The main take-home message for beekeepers from the 2004 research was similar to that in 2003, autumn preparation and management is vital to ensure a populous colony of bees is maintained through winter and early spring. The results of the research did not support ‘costly’ supplementary feeding practices to be carried out through winter.
 
 

	Frame divided into 5x5cm squares to place on top of combs to measure brood and pollen area.
	2004 trial site north of Young, final measurement August. Note open exposed nature of site.
	Comparing the attractiveness (chapter 12) of three types/sources of soyflour in bulk feeders. Wire placed over drum to keep sheep and other larger animals from consuming the flour.
	Weighing hives or components separately using a sheep weighing scales.
	Site of Tony’s apiary east of Temora, May 2004 trial. Note: lack of ground cover due to very dry conditions
	2004 trial – placement of feeding trays under lid. Soyflour, soyflour 50% - pollen 25% - yeast 25% or pollen.
	Comparison between the consumption of pollen on the left and soyflour on the right. Straight pollen was more palatable to bees.