Behavioral Differences of the Insect Morimus funereus (Coleoptera, Cerambycidae) Exposed to an Extremely Low Frequency Magnetic Field

Abstract

Changes in the behavior of Morimus funereus individuals were investigated as early manifestations of the contact of a living system with a changed environment primarily established via the nervous system. These experiments were aimed at revealing possible behavioral differences of a laboratory population of cerambycid beetle M. funereus in an "open field" before and after exposure to an extremely low frequency magnetic field (ELF-MF, 50 Hz, 2 mT). The experimental groups were divided into several activity categories and exposed to ELF-MF. The results showed that the activity increased in the groups with medium and low motor activity, but decreased in highly active individuals. High individual variability was found in the experimental groups, as well as differences in motor activities between the sexes, both before and after exposure to ELF-MF. According to preliminary results, we assume the changes of activity in both sexes after exposure to ELF-MF. The results showed a tendency toward locomotor activity decrease, the affect being more pronounced in females. As opposed to this type of activity, stereotypic activity of males was increased after the exposure, whereas females maintained the expected tendency of decrease. However, we did not obtain statistically significant differences because of a high individual variability and a low total number of individuals in the experiment (N = 28). Only a detailed analysis of the locomotor activity at 1-min intervals showed some statistically significant differences in behavior between the sexes.