Welcome to the third blog about wild pollinators in lucerne!
In the first two blogs, we saw that wild pollinators contribute on average A$22 M to the production of dryland lucerne seed, while their share in the production of irrigated lucerne is unknown. Now that we have some inkling of their value, it is time to explore some of these wild pollinators.
Which species are they, when are they active, where do they make their nests, how do we know they pollinate lucerne, and importantly, what support do they need from the surrounding landscape? That’s a lot of questions to answer! Today, we’ll start by finding out more about blue-banded bees.
A revision published earlier this year shows there are 14 species of ‘blue-banded’ bees in Australia, but not all have blue bands! As can be seen below, some have green, white or orange bands. In most species the hairbands are iridescent and their colour depends on the angle at which you look at them. While identification of the individual species can be tricky, there are only two blue-banded bee species in the lucerne growing area around Keith. Unfortunately, they only have Latin names, but let’s call them the green-blue-banded bee (Amegilla chlorocyanea; 25) and Murray’s blue-banded bee (Amegilla murrayensis; 32).
So how can you tell them apart? The last hairband is interrupted in female blue-green banded bees (25) but continuous in Murray’s bee (32). Furthermore, the hairy spot on the abdominal point of the females differs in shape. The males are more difficult to tell.
Blue-banded bees only live for about 5 – 6 weeks as an individual, but they have several generations, one following the other. In the lucerne growing areas around Keith, the bees are active from the about mid-October until the end of April. And because they are very common, this means that, whenever the grower decide to shut up the crop to induce flowering between October and February, blue-banded bees will be always be part of the mix!
Next week, we will find out how we know that these bees pollinate lucerne.