Cornfield ant

Systematic position: The cornfield ant (Lasius alienus) belongs to the order Hymenoptera, family Formicidae. This widely distributed species is commonly found in gardens, orchards, and fields, where it constructs its nests directly in the soil, beneath stones, or within the root zones of perennial plants.

Biology and life cycle: The colony life is based on a strict hierarchy: the queen, workers, and larvae. The nuptial flight of winged individuals occurs during the summer, after which queens establish new nests. Development from egg to adult depends on soil temperature and moisture levels. Colonies can persist for many years, gradually expanding and covering large areas of the foraging range.

Damage and harmfulness: The primary harm is caused by their symbiotic relationship with aphids, mealybugs, and psyllids. Ants "farm" these pests, protecting them from natural predators (ladybugs, lacewings) and transporting them to healthy plant tissues. By excavating tunnels, they disrupt the root systems of seedlings and young trees and contribute to soil desiccation around the roots.

Affected crops: The pest targets a wide spectrum of plants. Fruit trees (apple, pear), berry shrubs (currant, raspberry), and vegetable crops in greenhouses and open fields are particularly vulnerable. Plants weakened by ants become highly susceptible to fungal infections due to the presence of honeydew secreted by aphids.

Control measures: Management requires a comprehensive approach aimed at both eliminating the ants and controlling the pests they support. Recommended methods include:

• Installing sticky bands on tree trunks to restrict ant access to the canopy.
• Using specialized baits with slow-acting insecticides to eliminate the queen and the colony.
• Regular treatment of plants against sap-sucking pests (aphids) to deprive ants of their food source.
• Mechanical destruction of nests during soil cultivation in row spacing.
• Utilizing biological control agents that target ant colonies while minimizing environmental impact.