Effectiveness of crushed fresh leaves of Boscia senegalensis Lam Ex. Poir. harvested in Dakar and Richard Toll on Sitophilus zeamais (Motschulsky)

Abstract

The maize is one of the most produced worldwide cereals. Its conservation in stock is attacked by many pests that cause huge loss to the qualitative and quantitative level. Several alternative methods of control resulting in the insecticidal plants replace chemical pesticides. Among these methods, fumi-gation has proved very effective on insects’ food stored. In the present work, fumigating insects of Sitophilus zeamais to different doses of fresh crushed leaves of Boscia senegalensis showed strong insecticidal activity of this plant depending on the locality. Leaves of two localities, Dakar and Richard Toll have been tested. Statistical analysis of the mortality rate expressed in cu-mulative frequencies showed a significant difference (p<0.0001) between the groups tested and control groups. Leaves from Richard Toll gave 100% mortality within 24 h to 1 g / l while those collected in Dakar gave 100% in 24 h to a maximum dose of 9 g / l. We can explain this by significant differences in the rate of glucocapparin content in the leaves of this plant according to the locality and period of harvest. It should be noted that crops leaves were not done during the same periods. In this work, the best season to obtain a high efficiency is during dry season.