Effect of the Parasitoids Phymastichus coffea and Cephalonomia stephanoderis on the Coffee Berry Borer (Hypothenemus hampei) in Laboratory

Abstract

Aims: The coffee berry borer (Hypothenemus hampei) is the most important pest of coffee, causing severe damage to the berries. The chemical products commonly used for its control pose risks to human health and the environment. Therefore, this laboratory study was conducted to evaluate the effectiveness of two parasitoids, Phymastichus coffea and Cephalonomia stephanoderis, on coffee berry borer. Study Design: The study was carried out in laboratory conditions to minimize environmental variability. Place and Duration of Study: This study was carried out at the National Center for Agricultural Research in July and december 2023. Methodology: Parasitoids were reared under laboratory conditions on a natural substrate. The experimental design consisted of 200 parasitoids (100 P. coffea and 100 C. stephanoderis), 200 coffee berry borers, and 200 ripe coffee berries. Each experimental unit comprised 20 ripe berries, 20 borers, and 20 parasitoids. A completely randomized block design with five replications was implemented. Results: Results showed that the total mortality rates of the borers in the presence of the two parasitoids were 50% when parasitism occurred before fruit perforation and 60% when it occurred 28 days after perforation. Specifically, before fruit perforation, mortality was 30% with P. coffea and 25% with C. stephanoderis. When the parasitoids were introduced 28 days after perforation, mortality reached 20% with P. coffea and 22% with C. stephanoderis. Furthermore, the findings indicate that Phymastichus coffea targets adult borers, whereas Cephalonomia stephanoderis primarily attacks immature stages (larvae, pupae, and pre-adults). Conclusion: The combined use of both parasitoids proved to be the most effective strategy for controlling the coffee berry borer under laboratory conditions.