Population dynamics of root weevils in citrus

The goal of this study was to evaluate the population dynamics of citrus root weevils. Samples of the larval, pupa and adult phases were taken every 15 days in four citrus farms in Itapetininga, State of Sao Paulo, Brazil, between March, 2000 and February, 2002. The emergence of adults was evaluated in cages under plant canopy and the adult population at plant canopy with a beating cloth; larvae and the pupae in ditches opened in the soil, under plant crowns. Based on the population dynamics, the insects are univoltine. Most adults emerged from October to April, with peaks at the beginning of the period. Species Parapantomorus fluctuosus (Boheman), Naupactus cervinus Boheman and Naupactus versatilis Hustache were more frequent in Itapetininga, SP, although the peaks and times were different. Larvae occurred almost during the whole year, with population peaks from June to January. The number of curculionids was lower in the second year of the study for all insect phases, probably due to drought. Adults and larvae sampled, with beating cloths and in cages, could be used to detect, quantify and predict the occurrence of citrus root weevils.