Hickory tussock moth

The hickory tussock moth (Lophocampa caryae) is a member of the Erebidae family, specifically the Arctiinae subfamily. These insects are well-documented for the impressive appearance of their larvae, which are known to cause significant defoliation in various deciduous tree species across North America and beyond.

Host plants for this species are diverse, including hickory, walnut, oak, elm, ash, linden, and willow. The larvae are generalist feeders and can thrive on many different broadleaf trees. Severe infestations often lead to thin canopies, reduced growth rates, and increased susceptibility to other biotic and abiotic stressors, which negatively impacts the overall health of the forest or orchard.

The life cycle involves a single generation per year. Adult moths emerge in late spring to early summer to mate. Females lay clusters of eggs on the underside of leaves. Once the eggs hatch, the larvae congregate in groups during the early instars, feeding collectively, before dispersing throughout the tree canopy as they mature into later larval stages.

The caterpillars are characterized by dense tufts of white and black hairs. These hairs are not just for display; they contain urticating toxins. If a human touches the caterpillar, these barbed hairs can penetrate the skin, causing severe itching, redness, swelling, and dermatitis. Awareness of this risk is critical for gardeners and forestry workers when managing areas where these moths are present.

Effective management strategies require a combination of monitoring and intervention. It is recommended to perform:

• Visual inspections for egg clusters in late spring.
• Pruning of affected branches where colonies are localized.
• Application of bacterial insecticides like Bt when larvae are young.
• Use of chemical control if the infestation reaches economic thresholds.