South Australian bees suffer under high temperatures

Half Barrel Honey beekeeper Kerry Chambers, Renmark West, said the demand for pollination was growing on the back of an increased number of almond trees being planted in the Riverland.

"Some growers have deliberately pulled out vines to replace with almond trees, and more almond trees means there is a greater demand for bees," she said.

She said it would be a struggle to meet the overall demand in her area, and potentially across the state.

"Even amateur beekeepers like myself are having to lease out our hives to fill the shortfall of commercial beekeepers during this tough season," she said.

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The hive health deterioration during the summer has presented apiarists with a steep challenge to restore numbers in time for winter, when populations naturally dwindle.

"If beekeepers across the board aren’t able to increase their number of colonies leading into winter this will definitely affect the number of bees available for almond pollination later in the year," she said.

"I haven’t been able to split any of my hives to create new colonies because the existing colonies are just not strong enough."

Ms Chambers said most of her bees, which are placed in standalone hives in the backyards of host gardens, had only barely found enough nectar to survive, and were unable to create any surplus honey available for harvest.

The lack of colony strength in the face of heatwaves was largely due to nectar shortages, caused by reduced flowering in the absence of rain.

In addition, extreme heat led to wilting of flowers that did manage to grow.

SA Apiarists' Association president and Tintinara beekeeper Ben Hooper said the effect of flower wilting of crops such as lucerne had been detrimental for nectar availability.

"The wilting effectively lent itself to a shorter flowering period, and the heat took the end out of it for us," he said. 

"Lucerne is a major crop for us and, yes, we are there to pollinate, but it is also a really good, reliable source of nectar for making honey." 

In addition to the shortages, the hot conditions meant that bees switched from nectar foraging to water collection, slowing breeding within the hive and causing numbers to plateau or reduce.

"The bees run an evaporative cooling system to keep hive temperature between 32 degrees Celsius and 35C, and when the temperature rises above this bees start to change roles, with more going out to collect water as opposed to nectar," he said.

"Our game at the moment is making sure our bees are still breeding at least enough to build numbers to make it through winter."

SA APIARISTS' Association president Ben Hooper said beekeepers have been hit hard by hot and dry conditions, with many experiencing honey yields less than half their average this season.

Mr Hooper, who is based in Tintinara and runs 1700 hives, lost about 25 per cent of his own bee numbers, with every hive having lost strength.

"We know we're winding down but the heatwaves were really extreme events which dampened us personally and it did take its toll around the state with loss of hives," he said.

He said those who did not have the ability to relocate their hives suffered in the extreme conditions.

"The majority of beekeepers are migratory but there are an increasing number of people in the (Adelaide) Hills and on the Fleurieu who have 100 to 200 hives and really don't have the ability to move them much. They struggled the most," he said.

Mr Hooper said even those with a greater capacity to move hives saw limited benefits due to the widespread nature of the dry and hot weather.

"Even though we were moving the hives around, we weren't moving them for much gain," he said.