The effect of an ant-hemipteran mutualism on the coffee berry borer (Hypothenemus hampei) in southern Mexico

The indirect effect of an ant-hemipteran mutualism was investigated in the coffee agroecosystem of Southern Mexico. The ant, Azteca instabilis, forms a mutualistic relationship with the coccid, Coccus viridis, on coffee plants. Through field surveys and experimental studies, the indirect effect of this mutualism on the main coffee pest in the region, Hypothenemus hampei, the coffee berry borer (CBB), was investigated. Results indicate a significant negative relationship between the number of coccids on a plant and the proportion of berries with damage by the CBB. Results also indicate that the effect of the ants is significant on per plant basis but not on per branch basis. Finally, a significant negative linear relationship was found between ant activity and the time it took ants to remove artificially placed borers on coffee berries. This study indicates that the mutualistic relationship between Azteca ants and the coccids has a positive indirect effect on the plant by reducing the numbers of the main insect pest of coffee.