Coffee Berry Borer

The beetle is tiny and black to dark brown, so it is usually detected by its damage rather than by sight. The key field sign is a small, round entry hole, typically at the tip of the berry, where the female has bored in. Cutting open infested berries reveals galleries in the seeds and, often, several life stages of the borer together.

Because the entry hole and internal galleries are diagnostic, sampling and dissecting berries is the standard way to confirm infestation and assess its level.

Mated females bore into berries and lay eggs within the seeds, where larvae feed and develop into the next generation largely inside the same berry. Development is faster in warm conditions, and multiple overlapping generations occur through the fruiting period, so populations can build across a season and between successive crops.

The pest persists in berries that remain on the tree or fall to the ground after harvest. These residual berries are a crucial reservoir that seeds infestation of the next crop, which is why post-harvest sanitation is central to management.

Feeding inside the beans reduces the weight and number of marketable beans, damages their appearance, and can lower cup quality, while entry wounds can admit fungi that cause further deterioration. Because the damage is to the harvested product itself, even moderate infestation has a direct economic cost.

Coffee is the host of concern. Both of the main cultivated coffee species can be attacked, and the pest is found wherever coffee is grown in suitable warm climates.

Alcohol-baited traps are used to detect and track adult flight activity, and berry sampling — inspecting and dissecting berries for entry holes and internal stages — measures infestation on the tree. Monitoring the proportion of infested berries and the presence of residual berries after harvest guides timing of sanitation and other actions.

Management centres on sanitation and biological control within integrated pest management, because the concealed habit limits the reach of sprays.

• Practise thorough harvesting and post-harvest sanitation to remove residual berries that carry the pest over
• Conserve and use natural enemies, including parasitoid wasps and insect-pathogenic fungi
• Use traps to detect activity and help time management
• Manage shade and pruning to create conditions less favourable to the borer where appropriate
• Base any intervention on berry sampling and local thresholds