Blue-banded millipede

The Blue-banded millipede (Cylindroiulus caeruleocinctus) is a member of the class Diplopoda and the family Julidae. It is a common soil-dwelling invertebrate that thrives in moist environments rich in decaying organic matter. While primarily a decomposer, it can become a significant agricultural pest when natural food sources are scarce or its population density increases rapidly.

The range of crops susceptible to damage is extensive. The millipede primarily attacks subterranean parts of plants, including potato tubers, carrot roots, beets, and the delicate root systems of vegetable seedlings. These pests are particularly problematic in damp springs and during wet growing seasons, often causing severe damage to crops grown in heavy or poorly drained soils.

The biology of this species is characterized by a slow development cycle. Adults hibernate deep within the soil profile during winter and emerge to the surface as temperatures rise in the spring. They deposit eggs in clusters within the soil, and the resulting larvae undergo several molts before reaching maturity. Their cryptic nature makes monitoring and detection challenging until visible damage appears on the plants.

Damage caused by the Blue-banded millipede typically manifests as small, circular, or irregular pits and holes in the surface of root vegetables. These feeding cavities significantly impact crop marketability and serve as entry points for secondary infections like fungal and bacterial pathogens, which often result in total rot of the produce, both in the field and during long-term storage.

Management strategies require integrated pest management (IPM) techniques to be successful. Physical control combined with good cultural practices remains the primary defense. Key steps include:

• Improving field drainage to reduce the humidity levels preferred by millipedes.
• Removing crop debris and organic mulches that provide hiding places during the day.
• Deep tillage in the autumn to expose overwintering individuals to predators and freezing temperatures.
• Applying lime if the soil is overly acidic to alter the microenvironment against the pest.
• Using trap baits (such as sliced potatoes) buried slightly in the soil to attract and eliminate aggregations.