Chemical Composition and Insecticidal Activity of<i>Ocimum canum</i>Essential Oil Against Coffee Berry Borer,<i>Hypothenemus hampei</i>(Ferrari) (Coleoptera: Scolytidae)

Abstract

Abstract The chemical compositions of the essential oils of Ocimum canum Sims (Lamiaceae) areal part cultivated in Togo were investigated by GC-MS and tested for possible insecticidal activity against the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytinae) under laboratory. Eighteen constituents (98.5 % of the total oil) were identified in the volatile oil of O. canum leaf. The main constituents found in the oil were terpineol-4 (34.7 %), linalool (22.7 %), λ-terpinene (7.3 %), trans-thujan-4-ol (5.9 %), trans-α-bergamotene (4.9 %) and caryophyllene (4.6 %). Other components were also identified by at minor concentrations ranging from 0.12 % (Thymol) to 2.7 % (Limonene). In the insecticidal activity test, crude essential oil of O. canum emulsions of exhibited adulticidal activity against coffee berry borer and response was being dose-related. The LD50 were 320 ppm for O. canum essential oil and 450 ppm for endosulfan and the conventional insecticide used as standard, respectively. The results indicate that the O. canum essential oil has a potential insecticidal activity and can be used as active ingredient in natural and sustainable pesticide within an Integrated Pest Management approach to combat the coffee berry borer.