Natural allies in smallholder coffee landscapes

Coffee in Colombia is grown mainly on smallholder farms. Their most damaging pest is the coffee berry borer, a beetle developing inside the berry, where insecticides barely reach it. Spraying is often ineffective and harms beneficial insects. This research asked whether ants, spiders, beetles and parasitoid wasps already present on farms can suppress the pest. Twenty-four farms in Valle del Cauca were monitored for two years, alongside an experiment excluding natural enemies from coffee branches. Natural enemies reduced new infestations by about half. Natural enemies were most diverse on farms with shade trees and less frequent weeding, and infestation was lowest where forest and natural vegetation surrounded farms within 100 to 250 meters. Insecticide use weakened this benefit. Natural pest control therefore depends on supportive farm management and surrounding vegetation that helps natural enemies survive and suppress the coffee berry borer. This approach can be implemented at a scale that works for farmers and their neighbors.