Circadian rhythms of Blattella germanica L. as determined by microcalorimetry

Circadian rhythms of the male cockroach Blattella germanica L. have been observed in thermograms recorded from a microcalorimeter. These endogenous rhythms developed in unentrained individuals after 2 or more 24-h periods without light at 20 degrees C in the microcalorimeter. The rhythm can also be entrained with standard conditions LD 12:12 for a 3-day period.