Static electricity passively attracts ticks onto hosts

Electrostatic pollination by butterflies and moths

Animals, most notably insects, generally seem to accumulate electrostatic charge in nature. These electrostatic charges will exert forces on other charges in these animals' environments and therefore have the potential to attract or repel other objects, for example, pollen from flowers. Here, we show that butterflies and moths (Lepidoptera) accumulate electrostatic charge while in flight. Then, using finite element analysis, we demonstrate that when within millimetres of a flower, the electrostatic charge of a lepidopteran generates an electric field in excess of 5 kV m-1, and that an electric field of this magnitude is sufficient to elicit contactless pollen transfer from flowers across air gaps onto the body of a butterfly or moth. Furthermore, we see that phylogenetic variations exist in the magnitude and polarity of net charge between different species and families and Lepidoptera. These phylogenetic variations in electrostatic charging correlate with morphological, biogeographical and ecological differences between different clades. Such correlations with biogeographical and ecological differences may reflect evolutionary adaptations towards maximizing or minimizing charge accumulation, in relation to pollination, predation and parasitism, and thus we introduce the idea that electrostatic charging may be a trait upon which evolution can act.

Prey can detect predators via electroreception in air

Predators and prey benefit from detecting sensory cues of each other's presence. As they move through their environment, terrestrial animals accumulate electrostatic charge. Because electric charges exert forces at a distance, a prey animal could conceivably sense electrical forces to detect an approaching predator. Here, we report such a case of a terrestrial animal detecting its predators by electroreception. We show that predatory wasps are charged, thus emit electric fields, and that caterpillars respond to such fields with defensive behaviors. Furthermore, the mechanosensory setae of caterpillars are deflected by these electrostatic forces and are tuned to the wingbeat frequency of their insect predators. This ability unveils a dimension of the sensory interactions between prey and predators and is likely widespread among terrestrial animals.

A perspective on neuroethology: what the past teaches us about the future of neuroethology

For 100 years, the Journal of Comparative Physiology-A has significantly supported research in the field of neuroethology. The celebration of the journal's centennial is a great time point to appreciate the recent progress in neuroethology and to discuss possible avenues of the field. Animal behavior is the main source of inspiration for neuroethologists. This is illustrated by the huge diversity of investigated behaviors and species. To explain behavior at a mechanistic level, neuroethologists combine neuroscientific approaches with sophisticated behavioral analysis. The rapid technological progress in neuroscience makes neuroethology a highly dynamic and exciting field of research. To summarize the recent scientific progress in neuroethology, I went through all abstracts of the last six International Congresses for Neuroethology (ICNs 2010-2022) and categorized them based on the sensory modalities, experimental model species, and research topics. This highlights the diversity of neuroethology and gives us a perspective on the field's scientific future. At the end, I highlight three research topics that may, among others, influence the future of neuroethology. I hope that sharing my roots may inspire other scientists to follow neuroethological approaches.

Effects of Electromagnetic Radiation on Neuropeptide Transcript Levels in the Synganglion of Ixodes ricinus

Anthropogenic electromagnetic radiation is an important environmental factor affecting the functionality of biological systems. Sensitivity to various frequencies of electromagnetic radiation has been detected in ixodid ticks in the past. However, the physiological aspects of radiation effects have not yet been studied in ticks. In the presented experiment, 360 Ixodes ricinus ticks, 180 males and 180 females, were divided into 16 irradiated and 8 control groups. The irradiated groups were exposed to two different intensities of electromagnetic radiation with a frequency of 900 MHz at different lengths of exposure time. RT-PCR was utilized to determine the changes in mRNA levels in tick synganglia after irradiation. Four randomly selected neuropeptide genes were tested-allatotropin (at), FGLa-related allatostatins (fgla/ast), kinin, and arginine-vasopressin-like peptide (avpl). A significant decrease in transcript levels in all female groups exposed to higher intensity radiofrequency radiation for 1 to 3 h was found. After one hour of radiofrequency exposure, a significant downregulation in allatotropin expression in males was detected. A consistent downregulation of the at gene was detected in males irradiated with at a higher intensity. Unfortunately, the specific functions of the studied neuropeptides in ticks are not known yet, so a more comprehensive study is necessary to describe the effects of EMF on observed neuropeptides. This study represents the first report on the effects of the abiotic environment on tick neurophysiology.

Ticks' attraction to electrically charged hosts

Ticks are blood-feeding parasites with limited locomotion, known for transmitting multiple pathogens to vertebrates. England et al. suggest that ticks can be easily pulled, via electrostatic induction, toward charged hosts with fluffy coats that are prone to accumulate higher electrostatic potentials. Thus, static electricity may influence ticks' ecology and management.

An analysis of time-varying dynamics in electrically sensitive arthropod hairs to understand real-world electrical sensing

With increasing evidence of electroreception in terrestrial arthropods, an understanding of 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. After which, we explore how electrically sensitive hairs may respond to such stimuli. The main findings are: (i) oscillatory signals (elicited by wingbeats) influence the spatial sensitivity of hairs, unveiling an inextricable spatio-temporal link; (ii) wingbeat direction modulates spatial sensitivity; (iii) electrical wingbeats can be approximated by sinusoidally modulated DC signals; and (iv) 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 with 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.