A chronobiological approch to the study of the locomotor activity in genus dolichopoda (insecta : orthoptera). Preliminary observations on the populations of natural and artificial cave

Preliminary field observations suggested a different pattern in locomotor activity between natural and artificial populations of Dolichopoda cave crickets. To test and to quantify these differences we used a chronobiological approach and an automatic electronic device has been built for the continuous monitoring of the general locomotor activity of individual cave crickets. We modified a commercial microwave-based radar device and connected it to the computer. Crickets samples from two artificial caves and two natural caves, were individually monitored throughout 15 days in constant darkness and temperature. Time series were analysed by a Discrete Fourier Transform and chi-square periodogram. Data showed a variability of the circadian period significantly different in the two types of populations. Moreover, the spectral analysis and periodogram revealed the presence of ultradian rhythmicity.