NTUTM Professional Cup C4 Speech
Magnetoreception In Honeybee
Good evening everyone! Today, It’s my pleasure to share the interesting topic about honeybee. (Ask questions to the audience)
In animals, there are so many cues that they will use for orientation and navigation. Now, I briefly divided into three part. First is sun compass, Second, the landmark and the geomagnetism. Today, I’m going to focus on the geomagnetism.
We know that the earth is like a big magnet. Because of the steady signal it provided, the animals can use it to help them orientation and navigation. There are growing evidence showed that termites, flies and cockroaches would change their body axes with a rotated field in the rest. We can see there are so many examples from bacteria to animals in recent days. All these animals have been demonstrated that they can sense the field. How about honeybee?
So my first point is “Are honeybees able to sense the magnetic field?”Here is the evidences. In 1972, the researchers found that the homing behavior would change when extra field is added. It means that if I add the extra field between comb and flowers, the honeybees can not find the flowers’ position. Another evidence in 1982, Jong shows the orientation of comb building is associated with the field. It means that if I changed the magnetic field, the direction of comb building would also change. At last, the most important experiment. In 1998, Walker and Bitterman shows that free flying bees can be trained to discriminate the difference of magnetic fields. How to sense the magnetic field? The evidence showed that they sense the field based on their abdomen.
My next point is “Are different age honeybees have different magnetosense?” The newly emerged bee we call them nurse bee. After they grow up, we call them the forager. In order to test the honeybees magnetoreception, I use the classical conditioning to test them. (show the video) Knowing the honeybee can sense the magnetic field, then I use ICP-MS to quantify the iron concentration in their abdmen. The result in this figure shows that after 20 trails, there learning ability dramatically increased. And for the ICP-MS analysis, the iron concentration of elder adult bee is much more comparing with the younger adult bee. Because the forager will go out and find the pollen and honey back to the comb, so they need stronger magnetic sense ability. My conclusion is honeybee can sense magnetic field, honeybee will use magnetic field to help their orientation and navigation capabilities and honeybee can be trained and the sensitivity in foragers is better than nurse bees.
Thank you for your attention! J