Green-striped mapleworm

The Green-striped mapleworm (Anisota rubicunda) is a moth species belonging to the family Saturniidae. It is widely recognized as a significant forest and urban pest in North America, primarily targeting maple tree species. The insect is well-known for its striking appearance and its capacity for mass defoliation.

The preferred hosts for this species include the red maple, silver maple, and sugar maple. While they are specialized maple feeders, they may occasionally infest oak trees when populations are extremely high. The caterpillars are the primary life stage responsible for the economic and ecological damage observed in infested stands.

The life cycle of Anisota rubicunda typically involves one generation per year, though warmer climates may support multiple broods. Adult moths emerge in early summer to mate and lay eggs in large clusters on the underside of host leaves. The larvae go through five developmental stages, growing rapidly and increasing their consumption rate significantly in the final two stages.

Damage caused by this pest is characterized by heavy defoliation of the canopy. Young larvae feed gregariously, skeletonizing the leaves, while older larvae consume entire leaf blades, leaving only the midribs intact. Severe infestations can cause branch dieback, reduced radial growth, and tree mortality if the tree is subjected to stress over consecutive seasons.

Integrated Pest Management (IPM) for the Green-striped mapleworm focuses on minimizing chemical usage and preserving natural predators. Key strategies include:

• Hand-picking and destroying egg clusters if the trees are small and accessible.
• Applying microbial insecticides like Bacillus thuringiensis (Bt) during early larval stages.
• Encouraging natural biological controls such as birds and parasitic wasps.
• Monitoring seasonal moth flight patterns to time interventions accurately.