Effect of a terpene-based repellent on the infestations of coffee berry borer, Hypothenemus hampei (Ferrari) in commercial coffee orchards of Hawaii Island

Coffee berry borer (Coleoptera: Curculionidae) is the most damaging pest of coffee worldwide. In Hawaii, the pest was first detected in Kona district of Big Island in 2010 and has since spread to other coffee growing areas of the island and to Oahu. Female beetles (1.4-1.78 mm in size) bore into immature and mature coffee berries and construct galleries inside the beans where the eggs are deposited. Economic damage occurs due to abscission of immature berries, feeding by larvae on developing beans and quality or yield loss due to secondary infection by pathogens. To find alternate ways to manage this pest in Hawaii Island, we studied the effect of a terpene-based repellent on the proportion of berries infested and number of beetles captured on yellow sticky cards, at two commercial coffee orchards located in Kona and Kau. The repellent effect of the compound was significantly evident when compared against and an alcohol-based attractant. There was statistically significant reduction in number of new berries infested and number of coffee berry borers captured on sticky cards when the compound was used in combination with the attractant compared to the ‘attractant-alone’ treatment. A similar trend was observed, though statistically not significant, when the compound was used alone compared to a control. When the infestation on the treated coffee trees was tracked over time, it was shown that rate of infestation of was considerably slower on repellent-treated trees. Further studies are needed to streamline the method of application and maximize effectiveness of this compound.