Arion intermedius slug

Systematic position: Arion intermedius belongs to the phylum Mollusca, class Gastropoda, order Stylommatophora, and family Arionidae. It is a small terrestrial slug often recognized as a significant agricultural and horticultural pest in many temperate regions worldwide.

Host plants and damage: This pest is polyphagous and feeds on a wide range of vegetable, fruit, and ornamental crops. It frequently attacks young seedlings, lettuce, cabbage, potatoes, and strawberries. The damage is characterized by large, irregular holes in the foliage and surface tissue, often accompanied by the presence of dried mucus trails left on the plant surface.

Biology and life cycle: The slug thrives in moist and shaded environments. It is a hermaphrodite, and its reproduction cycle is highly sensitive to soil moisture and temperature. Eggs are laid in clusters within moist soil crevices or decaying organic matter. Both adults and eggs can overwinter in the soil, allowing the population to emerge quickly once conditions become favorable in the spring.

Host impact and harm: The slug poses a high risk to crops, particularly during wet seasons. Beyond the direct loss of plant tissue, Arion intermedius causes indirect harm by contaminating crops with its feces and mucus, significantly reducing the marketability of vegetables and fruits. Heavy infestations can lead to total crop failure, especially in early growth stages.

Protection measures: Management strategies should integrate multiple approaches to minimize slug pressure:

• Maintaining tidy garden beds by removing weeds and debris where slugs hide.
• Creating physical barriers around vulnerable crops using crushed eggshells or coarse sand.
• Using biological control agents such as predatory nematodes (Phasmarhabditis hermaphrodita).
• Implementing regular monitoring and using traps with fermented liquids.
• Applying safe molluscicides containing iron phosphate in the evening.