Plant population structure and insect herbivory on Solanum mauritianum Scopoli (Solanaceae) in southern Brazil: a support to biological control

Abstract

Solanum mauritianum Scopoli (Solanaceae), a native Brazilian shrub, has become naturalized and invasive in several countries. In South Africa, where invasions are severe, herbivorous insects that attack S. mauritianum in its native area have been considered for introduction as biological control agents. To assess the action of such herbivores on the plant, studies were carried out on a population of S. mauritianum in an area undergoing regeneration in southern Brazil. An analysis of the structure of that population was performed, as well as of herbivory by insects, in particular of Anthonomus (Curculionidae). The population structure showed an "inverted J" pattern in diameter classes, but not in height classes. Individual plants showed an aggregate distribution. The damage caused by Anthonomus did not amount to the loss of a large leaf area, but since it was inflicted on young leaves and in a large proportion, could lead to the survival decrease.