Diet and size influence sexual advertisement and copulatory success of males in Mediterranean fruit fly leks

1. The objective of the work reported here was to test the hypothesis that in insects that invest considerable energy in sexual displays and courtship, foraging successfully for food affects their subsequent performance and copulatory success in leks. Accordingly, the interactions between body size and diet on initiation of lekking behaviour and copulatory success in male Mediterranean fruit flies Ceratitis capitata (Diptera: Tephritidae) were investigated. 2. Protein-fed males were heavier and contained more protein and less lipid reserves than protein-deprived males. Protein-fed males were more likely to emit pheromone in leks and, consequently, were more likely to copulate than proteindeprived males. Furthermore, protein-fed males tended to start calling earlier than their nutritionally deprived competitors. 3. Though size was not related to initiation of lek behaviour, large males were more likely to copulate than small males. Among protein-fed males, large individuals tended to mate earlier than smaller individuals. 4. Generally, in lek mating systems where a considerable investment of time and energy is required by males, foraging successfully for nutritional resources prior to engaging in territorial or courtship behaviour is essential for reproductive success.