Aggressive Behaviour of Drosophila suzukii in Relation to Environmental and Social Factors

Aggression plays a crucial role in survival all across the animal kingdom. In this study, we investigate the aggressive behaviour of Drosophila suzukii, a known agricultural pest. Bioassays were performed between same sex pairs and the effect of environmental (food deprivation, sex, age and photophase) and social factors (non-social and social). Initially the inter-male and inter-female aggression was determined ethologically consisting of several behaviour patterns. Two hours starvation period increase locomotor activity of flies, promoting increased aggressive behaviour. Most of the behavioural patterns were common between males and females with a few sex-selective. Number of male encounters was higher in flies held in isolation than in those that had been reared with siblings whereas in case of females, only those that were isolated exhibited increased aggression. Females and males D. suzukii that were 4-day-old were more aggressive. In addition it is found that on the 3(rd) hour after the beginning of photophase, regardless of age, both males and females rise to high intensity aggression patterns.