Native Bees: Assessing Wild Bees

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With honey bees in decline, could wild bees be used to pollinate farmers’ crops? To find the answer, scientists need to assess how well wild bees pollinate. I’m Jim Metzner, and this is the Pulse of the Planet. Claire Kremen is an Assistant Professor of Conservation Biology at Princeton University.

“So, the first thing we do is simply to find out what bee species are visiting a given crop. We observe the species that are coming to the crop, and we collect individuals of each species so that we can identify them back in the lab. Then we do more detailed studies where we quantify the rates of visitation. And then, finally, we do pollination studies where we actually assess the efficiency of different bee species in pollination, and we can do this in a variety of ways depending on the crop.”

Well, here’s how they measure a bee’s pollination efficiency with a sunflower.

“A sunflower is actually a composite of thousands of tiny flowers called florets, and so, to do these experiments to assess the efficiency of different bee species, we put a pollination bag around the entire flower head before any of the florets open. And then when some of the florets open, we remove the bag and allow a bee to visit, but only one time. The bee will land on the flower head and will probably walk around visiting several different florets. As soon as the bee is finished, then we bag up the flower, and we don’t let any more visits happen. Then, much later, we go back to the flower and count the number of seeds that were produced from that single visit. In that way we can assess one – by doing this over and over again for a given species – what the average efficiency is of pollination for a single visit.”

We’ll hear more about wild bees in future programs. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.

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Native Bees: Assessing Wild Bees

Hear how scientists measure how well wild bees pollinate a particular crop.
Air Date:10/26/2004
Scientist:
Transcript:


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With honey bees in decline, could wild bees be used to pollinate farmers’ crops? To find the answer, scientists need to assess how well wild bees pollinate. I'm Jim Metzner, and this is the Pulse of the Planet. Claire Kremen is an Assistant Professor of Conservation Biology at Princeton University.

“So, the first thing we do is simply to find out what bee species are visiting a given crop. We observe the species that are coming to the crop, and we collect individuals of each species so that we can identify them back in the lab. Then we do more detailed studies where we quantify the rates of visitation. And then, finally, we do pollination studies where we actually assess the efficiency of different bee species in pollination, and we can do this in a variety of ways depending on the crop.”

Well, here’s how they measure a bee’s pollination efficiency with a sunflower.

“A sunflower is actually a composite of thousands of tiny flowers called florets, and so, to do these experiments to assess the efficiency of different bee species, we put a pollination bag around the entire flower head before any of the florets open. And then when some of the florets open, we remove the bag and allow a bee to visit, but only one time. The bee will land on the flower head and will probably walk around visiting several different florets. As soon as the bee is finished, then we bag up the flower, and we don’t let any more visits happen. Then, much later, we go back to the flower and count the number of seeds that were produced from that single visit. In that way we can assess one - by doing this over and over again for a given species - what the average efficiency is of pollination for a single visit.”

We’ll hear more about wild bees in future programs. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.

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