Pesticide use threatens biodiversity in farms and the matrices where they exist. In the coffee system, conservation biocontrol is a sustainable agriculture practice that has the potential to ameliorate the effects of pesticide by encouraging the presence of natural enemies. The coffee berry borer (CBB) remains the most important insect pest in coffee around the world. Spending the majority of its life cycle within coffee berries, the coffee berry borer evades topical applications of pesticide. Ants have been shown to be important predators of the coffee berry borer in field and laboratory settings. We assessed the ability of Wasmannia auropunctata, the little fire ant, to prey on adult female coffee berry borers in Puerto Rico. Over 20,000 coffee berries were assessed from 220 plants and two farms in Puerto Rico. W. auropunctata activity was determined via tuna fish baits in individual coffee bushes. There were significantly more attacked coffee berries in coffee bushes with W. auropunctata than in those without. However, coffee bushes with W. auropunctata had significantly less adult coffee berry borers inside the bored berries. These results suggest that W. auropunctata may be deterring other predators of the adult beetles before they penetrate the berries, and that W. auropunctata’s predation on the coffee berry borer is post-berry penetration, making W. auropunctata an important last line of defense against coffee berry borer infestation. Our results suggest that implementation of sustainable agriculture practices like conservation biocontrol could be important for the effective control of the CBB.