Determining the Origin of the Coffee Berry Borer Invasion of Hawaii

The coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae), was first discovered in coffee farms on the Big Island of Hawaii in 2010, after over 200 yr of borer-free coffee production. Because there are multiple pathways by which H. hampei could have entered Hawaii from >50 coffee-producing nations that harbor the pest, determining the invasion route requires genetic analyses. A previous study identified 27 H. hampei cytochrome c oxidase subunit I haplotypes from around the world using phylogenetic analyses to identify putative species. We sequenced cytochrome c oxidase subunit I from specimens collected in Hawaii and conducted phylogenetic and haplotype network analyses to trace the route of invasion. We conducted a network analysis to trace the most likely pathway that H. hampei could have taken to Hawaii and a phylogenetic analysis to assess clade support for broader groupings in the network analysis that are unlikely to have recently hybridized. The Hawaiian haplotype was identical to a haplotype from six Latin American countries, and our network analysis suggests the most likely route of invasion was from Kenya to Uganda to Latin America to Hawaii. Most coffee shipments from Latin America are fumigated, arrive on Oahu, and are processed before being shipped to other islands. Therefore, it is likely that H. hampei was accidentally transported to the Big Island by farm workers or other travelers from Latin America who carried borer-infested seeds in their clothing or luggage, or else by small quantities of illegally imported beans, although improper fumigation of shipments from Latin America remains a possibility.