Rust slug

Systematic position: the rust slug (Tandonia rustica) belongs to the phylum Mollusca, class Gastropoda, family Milacidae. It is a terrestrial pulmonate mollusc recognized by its distinctive keel on the dorsal side of its body, which serves as a key morphological identification feature for this species.

Host crops: this pest is a significant polyphagous mollusc that targets a wide variety of cultivated crops. It frequently causes economic damage to vegetables such as cabbage, lettuce, potatoes, and root crops, as well as various fruits, ornamental plants, and seedlings in both greenhouses and open fields.

Biology and life cycle: the rust slug relies heavily on moisture for survival and reproduction. Eggs are typically laid in moist, secluded spots within the soil or under organic debris. The life cycle consists of larval stages maturing into adults. Depending on climatic conditions, one or more generations may occur per year, with activity peaking during humid and mild seasons.

Nature of damage and economic importance: these slugs feed on plant tissues by rasping with their radula, creating large, irregular holes in leaves, fruits, and tubers. The characteristic silvery slime trails left behind not only indicate the presence of the pest but also facilitate the entry of secondary pathogens, such as soft rot bacteria, into the plant tissues.

Protection measures: effective management requires an integrated approach. Cultural practices include maintaining clear field margins, promoting proper drainage, and removing plant debris that provides shelter. Biological control or physical barriers can be effective in smaller gardens. Chemical control involves the use of molluscicides, such as iron phosphate or metaldehyde pellets, applied strategically around vulnerable plants.