Splitting of circadian rhythm of<i>musca domestica</i>flies with azadirachtin

In 46% of the azadirachtin injected flies a splitting of the activity rhythm into two components with the same period length was induced, whereas only one of the ethanol controls showed splitting after injection.

Abstract

Abstract The triterpenoid azadirachtin was injected in adult house flies and the effect on the circadian rhythm of locomotor activity studied. In most cases (83%) period was increased (by 0.4 h, as a mean), whereas flies injected with the solvent of azadirachtin, ethanol, increased period in 22% only (by 0.3 h, as a mean). In 46% of the azadirachtin injected flies a splitting of the activity rhythm into two components with the same period length was induced, whereas only one of the ethanol controls (2%) showed splitting after injection. LiCl added to the drinking water changed the activity pattern from splitting to arrhythmicity in about 50% of the azadirachtin treated flies. Abstracting keywords: circadian rhythm Musca domestica azadirachtinlithium chloridelocomotor activityarrhythmicitycoupling of oscillators Notes Department of Animal Physiology, Institute of Zoology, University of Warsaw, Poland. Institut für Biologie I, University of Tübingen, FRG.