THE MAGNETIC AND ELECTRIC-FIELDS INDUCED BY SUPERPARAMAGNETIC MAGNETITE IN HONEYBEES - MAGNETOPERCEPTION - AN ASSOCIATIVE LEARNING

Hairs on the abdomen of honeybees contain dendrites and a rod and ring structure composed of black particles, presumed to be superparamagnet ic (SPM) magnetite. The rod and ring were divided into compartments an d each compartment approximated by a dipole. The magnetic fields were calculated at a point P at various locations for a change of the exter nal geomagnetic field from zero to 0.5 G in 0.1 s. The magnetite ampli fies the external field at the rod/ring-dendrite interface. The induce d electric field and potential difference for a small circular area ar e in the order of 10(-7) V/m and 10(-13) V respectively. Mechanisms ar e proposed for amplifying the electric fields in the dendrite and in a n integrating nerve fibre. A hypothesis is developed for associative l earning of visual and magnetic stimuli. If magnetic and visual inputs are associated in the ganglion and in the brain, very small changes of either magnetic or visual inputs could be perceived. A bee could sequ entially follow the images associated with magnetic gradients on a clo udy day and find the food source.