Arion slug

Systematic position. The Arion slug (Arion) belongs to the phylum Mollusca, class Gastropoda, order Stylommatophora, family Arionidae. These terrestrial gastropods are characterized by the absence of a shell and a thick, muscular body capable of producing significant amounts of mucus for protection and movement.

Crops damaged. Arion species are notorious generalist herbivores. They cause significant damage to a wide range of horticultural crops, including leafy vegetables, strawberries, potatoes, and ornamental plants. Their feeding habits are particularly devastating to young seedlings, where they can completely destroy the crop in a single night.

Biology and life cycle. Arion slugs are hermaphroditic and highly reproductive. They lay hundreds of eggs in moist soil crevices or under debris. The development cycle depends heavily on humidity and temperature. During the day, they remain sheltered in cool, damp areas, emerging at dusk to feed. Their mobility allows them to migrate across fields, constantly expanding their feeding zones.

Nature of damage and harmfulness. The feeding symptoms involve irregular, jagged holes in leaves and deep, gouged cavities in fruits and tubers. Beyond physical consumption, the slime left behind by Arion slugs contains enzymes and potential pathogens, which accelerate the decomposition of damaged plant tissues and facilitate the spread of bacterial and fungal infections.

Control measures. Integrated management is essential for controlling Arion populations:

• Maintaining soil hygiene by removing weeds and dense vegetative debris that provide shelter.
• Employing mechanical barriers, such as copper tape or abrasive barriers like wood ash or crushed eggshells.
• Using bait stations with fermented liquids or iron phosphate-based pellets, which are safer for non-target species.
• Promoting natural predators like ground beetles, hedgehogs, and toads within the ecosystem.
• Applying targeted irrigation to manage soil moisture levels during peak slug activity.