When we think of bees and pollination, we might first imagine a honey bee finding nectar from flowers and bringing it back to it's hive to make honey. Yet bees are crucial for the function of many of our flowering crops, and part of the system of growing fruits we eat all the time such as eggplants, apples, beans, and pumpkins.
To grow those crops however, 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? Are crops which are grown in other regions visited by fewer types of bees?
It was this question that a couple of scientists from the Fenner School of Environment & Society decided to answer in a new study of the literature.
One of the researchers, Julian Brown says that while it's a pretty straight forward idea, it hadn’t been tested, possibly because of what was involved in getting the right data.
"We needed to know where different crops and plant families originated, which involved searching the archaeological and genetic literature," Julian said.
"For a crop species to be included in our study, it required that there were observations of flower-visiting bees in its region of origin and at least one other region, so we had to trawl the global literature for these observations."
This is the first time a study like this had been done on a global scale, extracting data from each of the over 300 studies that met their criteria to ensure it met quality standards.
The researchers found that indeed crops are visited by fewer bee genera (family of bee types) when they are grown outside the region in which they evolved. They also found that crops tend to be visited by more bee taxa when grown in the region of their family’s origin (which isn’t always the region where the crop itself evolved).
"This means that agricultural landscapes composed of native crops would be expected to support more native bees, and crops might experience lower pollination rates when grown outside their region of origin and their family’s region of origin," Julian said.
This is not to say that you need bees and crops from the same place of origin to work together - some bees can pollinate crops they did not evolve with.
Julian says there is a lot we still don’t understand about relationships between pollinators and crops.
"This is particularly so in Australia where this research has only really started happening in a big way in the last few years."