Response of insect activity rhythms to altered gravitational environments.

Researchers describe the development of the Beetle Activity Monitor (BAM), constructed to support an experiment with the desert beetle, Trigonoscelis gigas, proposed for the NASA-Mir program. The BAM tracks beetle movement via a wheel which turns as the animal moves in the cage. In addition to design features that conform to shuttle specifications and animal housing standards, it holds a maximum number of animals, allows for continuous recording of activity, and provides a controlled lighting environment. An experiment with 32 beetles collected data in 5-minute increments for animals exposed to constant darkness and 12-hour light-dark periods. Results of this experiment indicate that the light-dark cycle entrained the beetle circadian rhythm.