Abstract During coffee harvest, picked berries fall to the ground where they serve as a reservoir for the coffee berry borer (CBB) which then infest coffee berries on the trees. This study tested the effect of fallen CBB-infested coffee berries on the infestation of coffee trees ( Coffea arabica ). Three-year-old trees were treated with either 0, 1, 5, 10, 15, or 20 CBB-infested berries placed on the root vicinity. The CBB infestation of coffee trees was sampled every 30 days during 6 months for four coffee productive cycles. The experiment was set up at four different locations comprising different altitudes (1,218; 1,381; 1,470; and 1,700 m.a.s.l.) and the measurements were taken during 4 years where the climatic events of El Niño, La Niña, Neutral, and transitions El Niño/La Niña were present. The results show that CBB-infested berries left on the ground are a reservoir of CBB for 140 ± 8.2 days and infest developing healthy coffee berries. In a climate Neutral year, one CBB-infested ground berry left on the ground infested on average 590.2 ± 142.2 berries in coffee trees grown at 1,218 m.a.s.l. At the same altitude, one CBB-infested ground berry resulted in 151.5 ± 29.1 infested tree berries during La Niña year and 959.0 ± 89.6 during El Niño year. The CBB infestation was positively correlated with temperature and negatively correlated with altitude ( R 2 = 0.99 and R 2 = −0.96, respectively). This study highlights the importance of careful harvesting practices to prevent berries from falling to the ground, followed by ground sanitation to limit later infestation of the coffee crop.