Onion moth (Acrolepiopsis species)

Systematic position: The pest belongs to the order Lepidoptera, family Acrolepiidae. Acrolepiopsis betulella is a moth species recognized for its association with Allium crops, where it acts as a primary herbivore during the growing season.

Host plants: The primary hosts are members of the Amaryllidaceae family, specifically onions, garlic, and leeks. In cases of high population density, the larvae may infest various ornamental species within the genus Allium, leading to aesthetic and physiological damage to the host plants.

Biology and lifecycle: The species undergoes complete metamorphosis: egg, larva (caterpillar), pupa, and adult. Adults overwinter in sheltered locations, such as debris or field edges. In the spring, emergence coincides with the start of the onion growing season, when females deposit eggs directly onto the host plant tissues.

Nature of damage and harmfulness: Larvae mine the leaves, consuming the internal tissue and leaving the outer epidermis intact, which creates transparent-looking patches. Eventually, the damaged leaves collapse and dry out. Beyond the loss of leaf area, the tunnels act as entry points for pathogens, often resulting in bacterial rot in the bulb.

Control measures: Effective management relies on cultural practices like crop rotation and the removal of crop residues to destroy overwintering pupae. During the adult flight period, monitoring with pheromone traps is essential. Chemical control should be implemented early in the larval stage before the caterpillars penetrate deeper into the plant tissue.