CLEANING BEHAVIOUR IN DROSOPHILA-MELANOGASTER

A descriptive account of cleaning behaviour in D. melanogaster wild-type is given. The behaviour complex is analysed into seven leg cleaning and twenty body cleaning components. A method of obtaining ethograms is presented. The method consists of a series of transformations from event to written record with the aid of verbal symbols recorded on tape. Three systems of symbols of increasing degree of complexity are proposed, and their usefulness is illustrated by an actual ethogram. The problem of error introduced by the series of transformations is discussed. It is found that ethograms may be constructed by the method with reasonable degree of precision. The overall average relative percentage error is found to be approximately 16 per cent, one half of which is caused by the transformation from event to verbal record, the other half by the process of timing the duration of components from the tape. The magnitude of this error is dependent on the duration of components, and is free of cumulative effects. The organization of cleaning behaviour is discussed. The behaviour is not a random aggregate of a great variety of movements, but it is organized into a hierarchy of repetitive complexes from the daily cycles down to the smallest building blocks of the behaviour, the motor units. One of the most fundamental features of this behaviour is its repetitive character. © 1969.