Buzz about bumblebees

THE pollination potential of bumblebees is being investigated through a research project in Tasmania.

Bumblebees are a feral species first discovered in a garden in the inner Hobart suburb of Sandy Bay in 1992.

It is thought the bumblebee arrived from New Zealand.

More were soon found in the Tasmanian Botanical Gardens, and the large-bodied pollinator has been a regular visitor to Tasmanian gardens ever since.

Bumblebees are now being researched for their potential as alternative pollinators.

Jonathan Finch, an entomologist at the Tasmanian Institute of Agriculture, says the there are pros and cons in using the alternatives.

Mr Finch moved to the University of Tasmania in 2021 from Western Sydney University, where he studied pollination in mango, avocado and strawberry.

He is working on monitoring bumblebee queens using mini radio backpacks.

“It is early days, the study is still ongoing, but we hope to learn more about how queens forage and choose nesting sites,” he said.

“By doing this research we hope to learn more about why colonies fail and how we might potentially promote colonies on farms in the future.”

Research into alternative pollinators is being done to help reduce the reliance of fruit, nut and seed industries on the European honeybee.

This reliance on honeybees makes industries vulnerable to losses due to disease or parasites like the Varroa mite, which is now present on the Australian mainland.

Having more pollinator options will make these sectors less vulnerable.

The second reason is honeybees are not the best pollinator for every crop. For example, bumblebees excel in pollinating berries, tomatoes, cucumbers, cherries and more.

More diverse pollinators may help to improve fruit yields and quality.

Honeybees can be in high demand during the Tasmanian flowering season so having more pollinator options may help lower the cost for growers.

Bumblebees are also better suited to pollinating certain flowers than honeybees, delivering more pollen during each visit.

Unlike honeybees, bumblebees can be used to pollinate glasshouse crops and other forms of protected cropping, such as tunnels.

Honeybees get aggressive in glasshouses and pose a threat to workers.

They may also get sick in glasshouses due to the lack of pollen diversity.

In Europe and New Zealand, bumblebee hives are purchased annually by growers and placed into orchards and protected cropping environments like glasshouses.

They are relatively cheap at around $150 and are easy to post and move around.

Each hive may contain up to 500 workers during the peak of the season before dying off over the winter.

They can also be temporarily moved and sealed off if spraying is required.

Bumblebees collect and store nectar in their nests like honeybees, but it is considered not economically viable to collect because of the shape of the nest and amount present.

Other potential pollinators include hover flies which are excel pollinating many crops and can be reared on ch