Brown wood ant

Systematic position. The brown wood ant (Lasius emarginatus) belongs to the order Hymenoptera, family Formicidae. This species is widely recognized for its preference for nesting in crevices of wood, masonry, and trees, making it a common sight in both urban and rural agricultural landscapes.

Affected crops. While they do not consume plant tissues directly, they impact a variety of horticultural crops, including fruit trees (apples, pears, plums), grapevines, and various ornamental bushes. They are most problematic in orchards where they settle in aging or damaged wood.

Biology and life cycle. Lasius emarginatus is a polygynous species, meaning colonies can be supported by multiple queens, leading to rapid expansion. Like other ants, they undergo complete metamorphosis (egg, larva, pupa, adult). They are highly active foragers, constantly seeking carbohydrates in the form of honeydew.

Nature of damage and harmfulness. Their primary negative impact is the protection of aphids, scale insects, and mealybugs. By "herding" these sap-sucking pests and defending them from predators, the ants cause severe infestations that can stunt plant growth and transmit viral diseases. Furthermore, they accelerate the decay of trees by excavating wood already softened by rot.

• Installing sticky bands on tree trunks to prevent access.
• Treating aphid colonies to eliminate the ant food source.
• Using bait stations with slow-acting insecticides.
• Removing decaying branches and old, loose bark.
• Applying physical barriers or specialized insect-repelling powders.