Eucalyptus resinifera essential oils have fumigant and repellent action against Hypothenemus hampei

The coffee berry borer Hypothenemus hampei Ferrari (CBB, Coleoptera: Scolytidae) is one of the major pests of coffee causing damage in the field and in warehouses. This pest is mainly controlled with insecticides and repellents. Essential oils (EOs) have been investigated as an alternative to synthetic insecticides, however few studies on the use of EOs to control the CBB have been reported. In this study, the toxicity of essential oils (EOs) extracted from leaves of Eucalyptus and Corymbia species against the coffee berry borer (CBB) was evaluated. Of the eleven species investigated, chemical profiles of EOs of two plants (C. henryi and the hybrid E. alba × E. tereticornis) are reported for the first time. The toxicity of EOs was assessed by contact and fumigation. Fifty compounds were identified in the EOs, with 1,8-cineole, α-pinene, and citronellal being the most common. The EOs were more active by the fumigation route and the oils from E. resinifera caused the higher mortality to CBB. Moreover, the EO from E. resinifera was more toxic (LC50 = 64.72 μL/L) than garlic extract, used as standard, and showed rapid action (LT50 = 4.0 min). The toxic effect of E. resinifera EO towards CBB is due to a synergistic effect involving 1,8-cineole, α-pinene and p-cymene. The EO of E. resinifera was as repellent as the garlic extract to the pest. The potential use of E. resinifera EOs in CBB management is discussed.