Another great paper from the Lund group, this time regarding flight control in the nocturnal sweat bee Megalopta. Here, Baird et al compare Megalopta’s flight control with that of bumblebees. Both species were flown down tunnels with different visual patterns on the walls and, as predicted, both species showed an increase in flight speed in response to a reduction in horizontal optic flow. This confirms that Megalopta still rely on optic flow for some element of flight control even given the very low light levels. There were however two significant differences between Megalopta and the bumblebee. Megalopta fly much slower which may be a consequence of temporal summation strategies for dealing with low light levels. Also, when horizontal optic flow was removed from one wall of the tunnel, unlike bumblebees and honeybees, Megalopta did not fly closer to the wall with the reduced optic flow signal. This suggests that Megalopta may also be using non-visual flight control mechanisms or that they have to integrate optic flow signals over a much larger region of the visual field than day-active bees. Anyways, another piece of the nocturnal bee jigsaw is in place.
Baird E, Kreiss E, Wcislo W, Warrant E, Dacke M. (2011) Nocturnal insects use optic flow for flight control. Biol Lett. 2011 Feb 9