Mating Behavior of Ceratitis capitata1 on a Field-Caged Host Tree

We systematically observed the mating behavior of wild Ceratitis capitata (Wiedemann) flies released on a field-caged host tree (coffee) growing naturally in a plantation in Guatemala. The principal site of attempted copulation was the bottom surface of leaves. During late morning and early afternoon, males stationed themselves at this site, often forming leks, and released sex pheromone, thereby attracting virgin or otherwise receptive females. An additional important site of copulation attempts, particularly among already-mated females, and particularly during mid-morning and mid- to late afternoon, was the fruit, where males were arrested by oviposition-deterring pheromone deposited by females after egg laying. The principal strategy of males at this site appeared to be attempted seduction or rape of alreadymated or otherwise rather unreceptive females exhibiting oviposition behavior and little or no attraction to sex pheromone emitted by males on leaves. Possible selective advantages to males of each type of mate encounter pattern are discussed.