Mating tactics and courtship behavior inCleogonus rubetra (Fabricius) (Coleoptera: Curculionidae)

Females of the tropical weevilCleogonus rubetra oviposit into fruits of the leguminous treeAndira inermis, and larvae develop in the pulp and seed of these fruits. We hypothesized three alternative tactics by which males might secure matings. By using focal observations of males and by evaluating predictions specific to each hypothesis, we demonstrate that males search within aggregations of conspecifics for receptive females, and upon finding a suitable partner, males mount and perform courtship behavior consisting of stroking the eyes and sides of the female's abdomen. Males also stridulate and emit a sequence of short buzzing sounds. While mounted, males actively prevent rival males from mating with their partner. Males defend their mates for a mean duration of 3.7 h (including copulation). As predicted, paired males were larger than solitary individuals, although the difference was marginally nonsignificant. The overabundance of fruits relative to males, the prolonged period during which females are active, and the probability of last male sperm precedence are factors that may have contributed to the evolution of this female-defense tactic by males. Paired females were significantly larger than solitary females. We observed no competition among females for mates, and the correlation between elytron length of paired males and females was not significant.