Polydesmus collaris

Systematic position: This pest belongs to the phylum Arthropoda, class Diplopoda, order Polydesmida, and family Polydesmidae. These organisms are recognized by their flattened, segmented bodies, which allow them to maneuver effectively through soil pores and leaf litter in search of food.

Crops attacked: Polydesmus collaris acts as a polyphagous pest, causing significant damage to various agricultural crops. Preferred hosts include germinating seeds, young seedling roots, potatoes, carrots, and other root vegetables. They are particularly destructive in environments where organic matter is abundant and soil moisture remains consistently high.

Biology and life cycle: The life cycle is strictly regulated by moisture levels and organic content in the substrate. Females deposit eggs in clusters within soil cavities. Development involves several larval stages, with segments added at each molt. They typically remain in the upper layers of the soil, migrating deeper only during extreme temperature fluctuations or dry conditions.

Damage and harmfulness: Damage is primarily inflicted by adult and late-stage larval forms consuming plant tissues. They create deep, irregular gouges in roots and bulbs, which are often susceptible to secondary fungal pathogens. This feeding pattern severely weakens young seedlings, leading to yellowing, stunted growth, or total plant death.

Protection measures: Management of this pest focuses on environmental manipulation rather than chemical control.

• Proper soil drainage to reduce humidity levels.
• Removal of plant debris and dead wood where millipedes hide.
• Implementation of regular cultivation to expose the pest to surface predators.
• Using barriers around sensitive seedlings to prevent direct access.
• Applying biological control agents that target soil-dwelling arthropods.