Red wood ant

Systematic position: Formica truncicola belongs to the order Hymenoptera and the family Formicidae. Known as a red wood ant, this species is typically associated with forested areas. However, when orchards or gardens are established near these habitats, their foraging behavior brings them into direct conflict with horticultural practices.

Affected crops: While these ants do not consume plant tissues directly, they impact a wide variety of fruit trees including apples, pears, and plums, as well as berries and ornamental plants. Their presence is usually an indicator of an underlying pest issue, as they tend to gravitate toward plants already infested with sap-sucking insects.

Biology and life cycle: The colony life of Formica truncicola is highly organized, involving workers, queens, and larvae. They spend the winter in deep underground chambers or mounds. In the spring, they emerge and aggressively seek out sugar sources. This demand for carbohydrates is what drives them to cultivate and protect populations of aphids, scales, and mealybugs.

Damage and pest status: The primary harm is indirect. By protecting aphids from their natural predators—such as ladybugs and lacewings—the ants enable aphid populations to grow exponentially. This results in severe sap loss for the plant, leaf curling, stunted growth, and the development of sooty mold caused by the aphids' sugary waste, which blocks photosynthesis.

Protection measures: Effective management focuses on breaking the ant-aphid cycle.

• Installing adhesive bands on tree trunks to physically block worker access to the canopy.
• Applying bio-insecticides to manage aphid colonies directly.
• Removing vegetation that bridges the gap between the ground and tree branches.
• Using bait stations containing specific ant-targeted insecticides placed away from crops.
• Maintaining regular monitoring for early signs of aphid infestation.