Bee friendly gardening

When we think of bees, most people imagine honey bees and the sweet golden honey these industrious creatures produce. Beyond their ability to make honey, honey bees also play a vital role as pollinators (with an estimated economic value of $14.2 billion to the Australian economy), pollinating more than 50 essential food crops that underpin healthy balanced diets.

Our native bees

What’s far from common knowledge is that while honey bees are prolific pollinators, there are about 2,500 species of native bees in Australia that also play an important role as pollinators, not just in crop pollination but in maintaining biodiversity and ecosystem health.

These bees have co-evolved with native plants and in some cases, they have developed a unique relationship where specialist bee species are required to pollinate certain plants. The extinction of any one of these bee species could drastically affect some native plants, which in turn could potentially alter Australia’s unique ecosystems.

In any 100-kilometre radius, there are likely to be 200 native bee species, ranging in size from the largest species, the Great Carpenter Bee, which grows up to 24mm long, to the world’s smallest species, a Euryglossina quasihesma bee, which can be as small as 2mm long. Native bees come in a range of colours including black, red, green, yellow and even blue with stripes or polka dots.

The iconic Xylocopa (Lestis) aerata or Green Carpenter Bee is one of the better known Australian native bees, with some research undertaken to better understand the threats to its existence on Kangaroo Island after repeated bushfires. Other native bee favourites include the Banded Amegilla or Blue Banded species found across much of Australia, and the 11 native stingless bee species which, like honey bees, live in a colony with a queen but are only found in the northern tropical and subtropical regions. Most native bees have little if any profile in Australia, from the tiny Anthidiellum (Pycnanthidium) turneri found on the Queensland coast or the Megachile ustulata, known as a Firetail Resin Bee for its distinctive orange abdomen.

Honey bees, native bees and a range of other pollinating insects will co-exist where there are sufficient floral resources and habitat, but therein lies the problem. The biggest threats all bees face are largely due to human activities and include habitat loss, and competition for floral resources and nesting sites.

Habitat loss is driven by urban sprawl and increasing agricultural production, resulting in less flowers and nesting sites available. The competition for floral resources comes from all pollinating insects and animals, including birds, bats, beetles, flies and honey bees. Competition is not specific to honey bees and native bees. Habitat fragmentation occurs where remnant vegetation is disconnected and too far away for bees to travel between. Climate change and climate variability results in changes to flowering patterns, with flowering occurring sporadically and resulting in feed gaps for foraging insects.

Addressing habitat loss is an effective way we can support all bees, providing them with places to forage, live and breed.

Gardeners can help

There are three easy steps that home gardeners can take to support wild pollinators to ensure fruit trees, vegetables and flowering plants will perform at their best while maintaining biodiversity and ecosystem health:

• Plan a garden to provide flowers that bear nectar or pollen year round. Unlike honey bees that can fly up to five kilometres to forage, many native bees can only fly short distances, some less than 100 metres, so they need something flowering close by throughout spring, summer and autumn.
• Provide nesting substrates to support the 70% of native bees that reproduce underground. Make a ‘nesting ground mound’ by leaving some ground free from mulch, ensuring it is higher than mulched areas so birds don’t cover the bee nest entrances. Don’t over prune your garden and leave some hollow pithy stems for the cavity-nesting bees.
• Avoid insecticides that kill bees and other pollinators. Control weeds and garden pests by using mechanical or biological methods or substituting harsh chemicals with softer alternatives.

Whether we have a large or small garden, we can all play a part in rewilding our landscapes and making them more bee-friendly.

The Wheen Bee Foundation is a registered charity that promotes awareness of the importance of bees for food security, biodiversity and ecosystem health, and funds research and development activities that address the national and global threats to bees.

https://www.wheenbeefoundation.org.au/

Written by Fiona Chambers, Wheen Bee Foundation CEO.