Courtship of Drosophila Melanogaster in Large Observation Chambers: the Influence of Female Reproductive State

Abstract

1. Mixed sex groups of D. melanogaster were observed in large observation chambers in which food was available. The ratio of mated to virgin females was 3:1. 2. Fertilised females spent more time feeding than virgins and virgin flies spent more time in locomotor activity. 3. Most courtship behaviour took place on the food and consequently mated females received more courtships. 4. To test whether fertilised females were excluding virgin females from the food, groups of females without males were observed. The groups were composed either of virgin, or of a mixture of virgin and mated females. The results showed that even in the absence of fertilised females virgins fed less and were more active. There was no evidence that mated females excluded the virgins. 5. The adaptive significance of the observations is discussed in relation to dispersal from the site of eclosion, oviposition and remating. 1. Mixed sex groups of D. melanogaster were observed in large observation chambers in which food was available. The ratio of mated to virgin females was 3:1. 2. Fertilised females spent more time feeding than virgins and virgin flies spent more time in locomotor activity. 3. Most courtship behaviour took place on the food and consequently mated females received more courtships. 4. To test whether fertilised females were excluding virgin females from the food, groups of females without males were observed. The groups were composed either of virgin, or of a mixture of virgin and mated females. The results showed that even in the absence of fertilised females virgins fed less and were more active. There was no evidence that mated females excluded the virgins. 5. The adaptive significance of the observations is discussed in relation to dispersal from the site of eclosion, oviposition and remating.