Seed damage in Bauhinia pulchella Benth. (Caesalpiniaceae), Mimosa acutistipula Benth var. nigra Hub., Mimosa somnians H.B. ex Willd. (Mimosaceae) and Phaseolus linearis H.B.K. (Fabaceae), was studied to investigate defense against predators. The preference for larger seeds of Bauhinia pulchella by bruchids is a selection pressure for the plant to product smaller seeds, as a survival mechanism to scape predation. The impredictability of the number of viable seeds per pod in Mimosa somnians could represent a defense mechanism because it does not permit the optimization of the number of eggs laid in each fruit. The flattened seeds of Mimosa acutistipula limit the attack sucess of predator beetles. The high resistance of the pod skin and the hard compact seeds in Phaseolus linearis may be considered mechanical defenses. There is a con-elation between seed size and predator size in the species studied.
Seed predators; Bruchidae; Legumes