Peppered moth

Systematic position. The peppered moth (Biston betularia) belongs to the order Lepidoptera, family Geometridae. While famous in evolutionary biology for the phenomenon of industrial melanism, in agricultural contexts, it is recognized as a foliage-feeding pest that can cause significant damage to trees when local populations reach outbreak levels.

Host plants. This species is a generalist feeder (polyphagous). The larvae feed on a wide variety of deciduous trees and shrubs. Common hosts include birch, oak, elm, willow, and linden. Furthermore, the peppered moth is known to infest various fruit-bearing trees, such as apples, pears, cherries, and plums, often causing noticeable defoliation in home gardens and orchard settings.

Biology and life cycle. The species typically has one generation per year. The moths overwinter in the pupal stage, burrowing into the soil beneath host plants. Adult moths emerge between May and June. Females lay eggs in crevices in the tree bark. Upon hatching, the larvae, which resemble small twigs in color and shape, feed aggressively on leaves until they are fully grown, after which they descend to the ground to pupate.

Type of damage and economic impact. The larvae are responsible for the damage. They consume leaves, starting from the edges or creating irregular holes in the blades. If infestation is severe, trees can be stripped of their foliage, a process known as defoliation. This stresses the tree, inhibits growth, reduces potential fruit yield, and makes the plant more susceptible to secondary infections or severe weather conditions.

Protection measures. Effective management strategies involve:

• Autumn soil cultivation to disturb and expose overwintering pupae.
• Monitoring of adult moths using light or pheromone traps.
• Application of biological insecticides or selective chemical pesticides during early larval stages.
• Promoting biodiversity to encourage natural predators such as birds and parasitoid wasps that keep moth populations in check.