Non-contact measurement of a free flying bumblebee's (Bombus terrestris) electrical potential as it approaches and leaves a fixed electrode

With increasing evidence of electroreception in terrestrial arthropods,
understanding receptor level processes is vital to appreciating the
capabilities and limits of this sense. Here, we examine the
spatio-temporal sensitivity of mechanoreceptive filiform hairs in
detecting electrical fields. We first present empirical data, highlighting
the time-varying characteristics of biological electrical signals. We then
explore how electrically sensitive hairs may respond to such stimuli. The
main findings are: 1) oscillatory signals (elicited by wingbeats)
influence the spatial sensitivity of hairs, unveiling an inextricable
spatio-temporal link; 2) wingbeat direction modulates spatial sensitivity;
3) electrical wingbeats can be approximated by sinusoidally modulated DC
signals; and 4) for a moving point charge, maximum sensitivity occurs at a
faster timescale than a hair’s frequency-based tuning.  Our
results show that electro-mechanical sensory hairs may capture different
spatio-temporal information, depending on an object’s movement and
wingbeat and in comparison, to aero-acoustic stimuli. Crucially, we
suggest that electrostatic and aero-acoustic signals may provide
distinguishable channels of information for arthropods. Given the
pervasiveness of electric fields in nature, our results suggest further
study to understand electrostatics in the ecology of arthropods and to
reveal unknown ecological relationships and novel interactions between
species.