Green weaver ant

Systematic position. The green weaver ant (Oecophylla virescens) is classified within the order Hymenoptera, family Formicidae. These ants are well-regarded for their complex social behavior and their remarkable ability to construct elaborate nests by binding living leaves together using silk produced by their own larvae.

Affected crops. Primarily distributed across tropical regions of Australia and Oceania, this species impacts a variety of valuable crops. Major host plants include citrus trees, mangoes, cashew, and coffee plantations. Although they can be predators of certain pests, their presence often leads to severe secondary infestations.

Biology and life cycle. A single colony of green weaver ants can contain hundreds of thousands of individuals. The life cycle undergoes complete metamorphosis, including egg, larval, pupal, and adult stages. The construction of nests is a cooperative effort where workers physically pull leaves together while others manipulate larvae to use their silk as a natural adhesive.

Nature of damage. The primary economic harm is caused by the ants' symbiotic relationship with honeydew-producing insects such as aphids, scale insects, and mealybugs. By protecting these pests from natural predators and parasitoids, the ants enable them to proliferate, causing plant stress, stunted growth, and the development of sooty mold across leaves and fruits.

Control measures. Integrated pest management (IPM) is essential for controlling green weaver ant populations. Key strategies include:

• Installation of sticky barriers on tree trunks to prevent access.
• Targeted pruning and destruction of nests during the early morning.
• Application of selective insecticides to manage honeydew-producing insects.
• Maintaining healthy tree canopies to discourage nest establishment.