The effectiveness of a biopesticide in the reduction of coffee berry borers in coffee plants

Context. Crop pest outbreaks are expected to become more frequent and unpredictable due to climate change, posing risks to ecosystem health and farmers’ livelihoods. At the same time, there is growing evidence that chemical pesticides can persist in the landscape and contribute to land degradation. The use of natural pesticides in place of chemical pesticides is hoped to manage pest outbreaks while also restoring pollinator populations and improving the quality of arable land. During the 1970s, many countries committed to promoting and legislating Integrated Pest Management (IPM) strategies (encouraging natural and holistic approaches to pest management), often including using natural pesticides, known as biopesticides. Objective. We assessed the effectiveness of a biopesticide on coffee berry borer (CBB; Hypothenemus hampei) presence in 57 small-holder coffee home gardens in West Java, Indonesia across three years. Methods. Prior to the application of the biopesticide, we randomly chose ten coffee plants from each field and recorded the proportion of healthy berries per plant (berries without pest infestation) as a control. In April 2020, we distributed the biopesticide in each of the 57 coffee home gardens and repeated the above experiment. The biopesticide was redistributed in October 2020 and April 2021. We repeated the experiment for the last time in April 2021. Results and conclusions. We found that CBB presence significantly decreased, with an inverse relationship between distance to natural forest and CBB presence and a positive relationship between shade cover and CBB presence. We also interviewed farmers in April 2021 to investigate their perception of the effectiveness of the biopesticide and 87% of farmers thought it was more effective than conventional pesticides. Significance. We contribute to the growing literature on the effectiveness of natural pesticides through assessing farmers’ perceptions of these methods and providing empirical evidence for their effectiveness in remedying CBB infestation. We hope that this study will empower farmers to make conscious land-use choices and provide government authorities with evidence to support increased accessibility to biopesticides