Tuesday, 14 June 2016

Bumblebees Are Amazingly Smart: They Detect Weak Electric Fields with Their Mechanosensory Hairs

Bumblebees are amazingly smart. Image courtesy of Bernie Kohl, public domain.

Joel Kontinen

Small creatures can be surprisingly intelligent. Ants seem to be able to count. Honeybees might build a mental map and their waggle dance is truly amazing.

Previous research has shown that bumblebees (Bombus terrestris) used a flower's electric field to find out whether other bumblebees had already been to the flower and whether it was worth going to.

A new paper published in PNAS looks at bumblebees’ ability to detect weak electric fields:

Bumblebees (Bombus terrestris) use information from surrounding electric fields to make foraging decisions. Electroreception in air, a nonconductive medium, is a recently discovered sensory capacity of insects, yet the sensory mechanisms remain elusive. Here, we investigate two putative electric field sensors: antennae and mechanosensory hairs.

What follows does not sound like it’s the work of the Blind Darwinian Watchmaker and reminds us that despite their name, bumblebees are anything but bumbling creatures:

Examining their mechanical and neural response, we show that electric fields cause deflections in both antennae and hairs. Hairs respond with a greater median velocity, displacement, and angular displacement than antennae. Extracellular recordings from the antennae do not show any electrophysiological correlates to these mechanical deflections. In contrast, hair deflections in response to an electric field elicited neural activity. Mechanical deflections of both hairs and antennae increase with the electric charge carried by the bumblebee. From this evidence, we conclude that sensory hairs are a site of electroreception in the bumblebee.

The animal kingdom abounds with designed features that challenge Darwinian evolution, for instance jellyfish navigation, the gliding skills of lemurs, gecko feet and the co-ordinated flight of tens of thousands of starlings.


Sutton, Gregory P. et al. 2016. Mechanosensory hairs in bumblebees (Bombus terrestris) detect weak electric fields. Proceedings of the National Academy of Sciences.