Bees are crucial for the function of many of our crops, and part of the system of producing food such as apples, almonds, berries, beans, eggplants and pumpkins - beyond just making honey.
To produce those crops, the plants need to produce seeds - and this is where bees come in to the picture. By moving from plant to plant, bees take pollen with them, transferring it from the male parts of flowers (anthers) to the female parts of flowers (stigma). This is how plants produce seeds and fruit via sexual reproduction.
But just as not all crops are the same, neither are bees - and with much of our food being grown globally, with plants dispersed far outside their place of origin, how does this change the relationship between bees and plants? Our research examines these relationships and asks questions such as:
- Do native bees pollinate non-native crops?
- How does their pollination compare with the service provided by European honey bees?
- Can we manage agricultural landscapes to maximise the effectiveness of crop pollinating native bees?
Academic paper - Global-scale drivers of crop visitor diversity and the historical development of agriculture - can downloaded for free here.
The berries and the bees
We conducted research in rubus berry orchards (blackberry and raspberry) in the Yarra Valley region of Victoria, to better understand the role of native bees in pollinating these crops.
Our research showed that native bees pollinate blackberry flowers just as effectively as honeybees. The most common native bees were reed bees (Exoneura) and white-banded bees (Lasioglossum). Reed bees create nests by tunnelling in to pithy stems and we found them nesting in raspberry and blackberry canes. Because they do not tunnel through live tissue they do not harm the plant.
This means that the rubus berry orchard environment provides both a home (nest) and food (flowers) for them to prosper! In one site the density of reed bees was estimated to be 3,000 per hectare. Reed bees are providing an important free pollination service in these crops, and growers could benefit by paying attention to maintaining this mutually beneficial arrangement.