Native bees in cropping systems

Branding Ag Excellence
Video Transcript

There are several native bees, especially ground nesting native bees, that profit from wheat – such as the Cape Wheat here and will pollinate crops such as Canola here. We know that when the Canola crop is pollinated well, the yield increases about 30 percent. Now, honeybees pollinate Canola and native bees do their bit as well.

Species of Native Bees

The Canola crop and the other crops actually have a lovely area of open space in between the plants, and so, it’s very suitable for bees to nest in. Now, our most common family of bees in Australia are what they call the Silk Bees. With the Silk Bees, we find a number in Canola crop but not heaps. They will often rely on native vegetation.

A second, quite large group that we find are the are the Furrow Bees. And the Furrow Bees are much more generalist bees. They will go, many species will go, for almost anything. That is the main species that we find in the crops here, and in a field like this, we would find around 10 species of Furrow Bees.

That is only possible if there is a no-till strategy, because as soon as a farmer starts to work the ground deeper, the nest will be destroyed, the brood will not survive the winter, and there will not be any bees nesting in the Canola. It’s not always very easy for those bees because now it’s a feast, or flowers, right next to me, but next year there might be grains in this crop, and when there’s grains in this crop, there’s no food for bees.

The bees will still nest there, so it’s important to know that they’re there, and in those years that there are grains here, the bees will profit more from the native vegetation and the weeds surrounding the crop so that in the good years when there is Canola there the bees will again pollinate the Canola.

Native Bees Susceptible to Insecticides

Think when you spray because when it is necessary to spray an insecticide, well, it’s best to choose the softest option, option for bees obviously. But might be better to spray before the crop’s in flower. Or delay it preferably until after the crops finish flowering because otherwise we will kill the bees that visit the crops as well. Especially if you use systemic insecticides which are immensely detrimental to all insects including these.

Do a bit of research with traps that are specific for native bees, and what we’ve been doing is putting these traps at different distances from the native vegetation, and into the crop. And what we’re finding is that even when we put these traps three hundred meters into a grain crop, there are still native bees out there, even though there are no weeds, they have nests out there, and those nests will be re-used year after year.

Katja Hogendoorn, from the University of Adelaide, discusses native bees in broad acre cropping systems.

There are several native bee species that will pollinate crops. Yield increases can be up to 30% in some broad acre grain legume and 10% in canola crops if pollination is effective. No till farming systems provide an ideal environment for native bees to nest and thrive in.

They need flowers to sustain them after the crop has finished flowering. Insecticide use needs to be managed carefully to impacts on native bee populations. This work is part of a project supported by the Northern Yorke Natural Resources Management Board.

Leave a Comment

Back to top