Use of Essential Oil of Eucalyptus globulus Leaves against Sitophilus zeamais Motsch

Abstract

Aim: To assess in laboratory conditions, the efficacy of essential oil of Eucalyptus globulus leaves against the infestation due to maize weevil Sitophilus zeamais, the main insect pest of stored maize grains. 
 Study Design: This study was conducted as two separate trials. Each trial was performed using a completely randomized design with 5 treatments repeated 3 times.
 Place and Duration of the Study: The study was conducted in the laboratory Unit of Phytopathology and Crop protection, Faculty of Agronomy, University of Kinshasa, between February and April 2018. 
 Methodology: Two trials (in Petri dishes and in cotton bags) were conducted separately from each other, while treatments used were the same. Trials were conducted according to a completely randomized design with 5 treatments repeated 3 times. Treatments used corresponded to 5 different volumes (0, 15, 20, 25 and 30 ml) of essential oil of Eucalyptus globulus leaves. In each trial, data collected were the rate of S. zeamais mortality and percentage of maize grains damaged. 
 Results: In general, statistical analysis showed significant differences (P<0.05) among treatments used. There was variation over time of the percentage of S. zeamais mortality as a function of the volume of essential oil of E. globulus. The volume of 30ml of essential oil caused higher mortality compared to other treatments. The percentage of maize grains damaged increased on control, while it decreased on maize grains treated with essential oil of E. globulus leaves. 
 Conclusion: The results of the present study revealed that essential oil of E. globulus leaves can help to protect maize grains stored against infestation due to maize weevil, Sitophilus zeamais.