“Electrorepellancy” behaviour of Periplaneta americana exposed to friction charged dielectric surfaces

We analysed the behaviour of the American cockroach, Periplaneta americana, to electrostatic fields induced on frictionally charged Polytetrafluoroethylene (PTFE) in Y-choice bioassays. Under red light conditions cockroaches significantly avoided electrostatic fields (p<0.05). The removal of specific combinations of sensory structures (the antennae, palps and cerci) had no effect on the abilities of cockroaches to avoid electrostatic fields (p<0.05 in all cases). Under white light conditions intact cockroaches significantly avoided electrostatic fields (p<0.05), but the proportion of individuals showing avoidance was significantly less than that under red light (p<0.05). Ablation of the cerci alone had no effect on the abilities of cockroaches to avoid electrostatic fields (p<0.05); however, when the antennae, or antennae and palps were removed, however, cockroaches failed to avoid electrostatic fields (p>0.05). These results show that P. americana avoid electrostatic fields irrespective of visual input, but that under white light they made more errors with more individuals walking on the charged surface. Ablation studies under white light reveal that anterior sensory structures may play a key role in electrostatic field detection.