Effects of constant or variable thermal rearing condition: a behavioural approach using an automated tracking system in Blaberus craniifer

An automatic tracking device was used to investigate exploratory behaviour of the cockroach, Blaberus craniifer, with regard to the influence of reari ng temperature. Two groups were tested, one under variable rearing temperat ure, the other under constant rearing temperature. Rearing temperature infl uenced both the rate of decrease of linear speed and the spatial occupation of an open arena. Linear speed decreased with time and was higher during t he first 10 minutes of recording for the animals reared under constant temp erature conditions. The decrease fitted a linear model for the variable tem perature group, whereas it was steeper than exponential for the constant te mperature group. Frequency of occupancy in the peripheral zone of the arena was not affected by time and was always higher for the animals of the cons tant condition group. The results are interpreted as a function of the diff erent thermal rearing conditions. (C) 2000 Elsevier Science Ltd. All rights reserved.