Myrmelaschista schumanni

Myrmelaschista schumanni is an ant species recognized as a significant pest in tropical coffee cultivation. Belonging to the family Formicidae, these ants are known for their habit of nesting within the living tissue of plants, which distinguishes them from typical ground-dwelling ant species.

The primary hosts for this pest are coffee trees (Coffea species). The ants penetrate the branches and stems to establish their galleries, causing structural damage. This internal tunneling impairs the vascular system of the tree, hindering the flow of water and nutrients essential for development and fruit production.

The biology of these ants is defined by a mutualistic relationship with scale insects or mealybugs. The ants protect these sap-sucking insects from predators in exchange for honeydew, a sugary substance secreted by the scales. This synergy leads to massive infestations, where the combined pressure of the ants and the scale insects accelerates the decline of the coffee tree.

Damage to the plant is twofold: direct mechanical harm from tunneling and indirect physiological stress from the scale insect population. Symptoms include stunted growth, chlorosis, the drying of terminal branches, and the onset of sooty mold on the leaves and berries due to the honeydew deposits.

Effective management strategies include:

• Systematic pruning of infested branches to disrupt colony development.
• Chemical control targeting both the ants and the scale insect population simultaneously.
• Maintaining field hygiene to prevent the buildup of pest-supporting conditions.
• Encouraging natural biological controls such as specialized parasitic wasps and predatory beetles.