The ecology of electricity

: Pollination, parasitism, and predator-prey interactions

Abstract

Electricity is an intrinsic component of the universe. As such, electricity is omnipresent in the natural world; not only in the abiotic realm but the biotic realm too. This is manifested in the prevalence of electric charges in or on organisms and the physical environment with which they interact. Because electric charges interact with other charges
to generate forces, electricity inevitably influences biology. Whilst this is well-appreciated at smaller scales, few consider the role of electricity in ecology. To rectify this, my thesis argues that naturally occurring electricity should be considered a major mechanistic driver within ecological interactions, and the resultant evolution of life in the universe. To this end, a literature review is conducted assessing existing electric ecology research. Subsequently, I apply an interdisciplinary approach to three of the most important ecological interactions: pollination, parasitism, and predator-prey interactions. Deploying behavioural, biophysical, computational, mathematical, and morphological techniques, I explore the role of naturally occurring electricity in these key ecological contexts. I demonstrate that butterflies and moths accumulate sufficient electrostatic charge to attract pollen across air gaps, resulting in contactless pollen transfer, and observe that charge variations exist between lepidopteran species that correlate with morphological, ecological, and biogeographical characteristics. I show that parasitic ticks can be attracted across air gaps of several body lengths, improving their host-seeking efficiency. I elucidate the mechanisms of this process, showing that it relies upon an electrical polarisation within the tick body. I demonstrate that electroreception can be used by terrestrial animals to detect their predators, showing that caterpillars respond defensively to the electric fields of predatory wasps, and reveal the mechanism of this detection to be electrostatic actuation of mechanosensory setae. Lastly, I show that treehoppers are similarly capable of detecting electricity, and that their morphological diversity may be driven by specialisation for aerial electroreception

Date of Award	3 Oct 2023
Original language	English
Awarding Institution	University of Bristol
Supervisor	Daniel Robert (Supervisor) & Marc W Holderied (Supervisor)