Greek processionary moth

Taxonomic position: Thaumetopoea hellenica is a species of moth within the order Lepidoptera and the family Thaumetopoeidae. This pest is a significant defoliator of coniferous trees, widely recognized for its social caterpillar behaviour and impact on forest health in the Mediterranean region.

Host plants: The primary hosts for this species are pine species, specifically the Calabrian pine (Pinus brutia) and the Aleppo pine (Pinus halepensis). The moth thrives in dry, warm climates where these specific pines form extensive forest ecosystems.

Biology and life cycle: The life cycle is complex, involving eggs, larvae, pupae, and adults. After overwintering, young larvae emerge and form communal silken nests on pine branches. These nests serve as a thermoregulatory structure where the larvae congregate during the day, emerging at night to feed on pine needles in coordinated "processions".

Type of damage and economic impact: The larvae cause extensive defoliation by consuming needles. This leads to weakened tree vigor, reduced growth rates, and increased susceptibility to secondary pests and diseases. Moreover, the urticating hairs of the caterpillars are a major health hazard, capable of inducing severe allergic reactions in humans and animals upon contact.

Protection and control measures:

• Manual removal and destruction of silken nests during the winter months before larvae mature.
• Application of biological insecticides containing Bacillus thuringiensis to target early-stage larvae effectively.
• Deployment of pheromone traps to monitor adult male populations and disrupt mating cycles.
• Enhancing forest biodiversity to encourage natural predators, including predatory wasps and insectivorous birds.