[Free course of circadian rhythms in Trigonoscelis gigas beetles after space flight]

Before and after space flight on Cosmos-1887 motor activity of Trigonoscelis gigas beetles kept in darkness was recorded. After flight 6 out of 7 beetles showed reduction of periods of free running circadian rhythms. The fact that the change was not observed in controls suggests that it can be attributed to the effects of O G. It is assumed that in space flight the biological requirements for the day duration are modified.