Persistance of the insecticidal activity of five essential oils on the maize weevil Sitophilus zeamais (Motsch.) (Coleoptera: Curculionidae).

Essential oils of aromatic plants are popularise as protectant with low persistance. The evaluation of this duration of activity was carried out for five aromatic plants: Annona senegalensis (Annonaceae), Eucalyptus citriodora et Ecalyptus saligna (Myrtaceae), Lippia rugosa (Verbenaceae) and Ocimum gratissimum (Lamiaceae). They have significant insecticidal activity on S. Zeamais, on the first day of application, this activity decreases after 2 or 4 days. After 8 more than 50% of the efficacy is lossed for all the plants excepted A. senegalensis.