Leaf-cutting ant

Systematic position. Acromyrmex octospinosus is a member of the order Hymenoptera and the family Formicidae. Known as leaf-cutting ants, they are highly advanced social insects that have co-evolved with specific types of fungi. They represent one of the most persistent and destructive pest groups in various agro-ecosystems across the Americas.

Host plants. These ants are extreme generalists, feeding on a vast array of botanical species. Major economic crops at risk include citrus orchards, coffee and cacao plantations, sugar cane, and a wide variety of vegetable crops. Their ability to defoliate large plantations in a matter of days makes them a primary target for agricultural pest control programs.

Biology and life cycle. The colony structure revolves around a single queen, who establishes a new nest by bringing a starter culture of symbiotic fungus. Development proceeds through complete metamorphosis (egg, larva, pupa, adult). The colony functions as a superorganism, where caste division ensures optimal foraging efficiency, nest sanitation, and fungal garden maintenance.

Damage and severity. The primary form of damage is defoliation. Foraging workers cut semicircular sections from leaves, transporting them to the nest to serve as a growth medium for their fungus. This aggressive harvesting leads to severe plant stress, reduced photosynthetic capacity, stunted growth, and significant yield losses, often causing the death of younger plants or vulnerable seedlings.

Protection measures. Effective control requires disrupting the colony’s symbiotic relationship with the fungus. The most common and effective method is the use of slow-acting toxic baits that are carried into the nest, eventually eliminating the queen and the fungal garden. Other strategies include the application of contact insecticides along foraging trails and physical barriers applied to tree trunks to prevent access to the foliage.