Rhinocricus bernardinensis

Rhinocricus bernardinensis is a species of millipede belonging to the class Diplopoda and the order Spirobolida. Like other members of this group, they are characterized by having two pairs of legs on most of their body segments.

Adult specimens possess a cylindrical, robust body with a dark brown to blackish coloration. Each body segment is marked by distinct rings, which is a key identification feature for this specific millipede species.

These millipedes thrive in moist environments and are typically found in the upper soil layers, under leaf litter, or in decaying wood where humidity remains consistently high throughout the day.

The life cycle involves multiple molting stages, during which the millipede grows by adding more segments to its body. They spend the majority of their time in the soil, which provides both protection and food resources.

They are primarily nocturnal and show increased movement during periods of high humidity or after irrigation. Their biological adaptation allows them to survive in various organic-rich soil substrates.

Rhinocricus bernardinensis is known to cause significant damage to vegetable crops, berries, and seedlings. They feed on tender roots, stems, and underground parts of plants, often causing irreparable damage.

In greenhouses, where high humidity is maintained, these millipedes can proliferate rapidly, posing a severe threat to young transplants. They often target the root hair zone, impairing the plant's ability to absorb nutrients.

Root crops such as carrots, potatoes, and beets are particularly vulnerable. The millipedes bore tunnels into the tissue, creating entry points for secondary infections like fungal rots and bacteria, which can destroy the crop.

For seedlings, the damage is often fatal. By chewing through the base of the stem or the root system, they prevent the plant from establishing properly, leading to wilting and eventual death of the crop.

• Consumption of seeds and germinating plant tissues.
• Destruction of fine root hairs and lateral roots.
• Boring into tubers, leading to storage rot.
• Facilitating the spread of soil-borne plant pathogens.

Visible signs of infestation include wilting of plants despite adequate soil moisture and the presence of small, irregular holes on roots and underground stems upon inspection.

During a close examination of the soil around the base of affected plants, one may encounter the millipedes curled in a spiral shape, a typical defensive posture for this species when disturbed.

The presence of fine, dark granular fecal matter in the rhizosphere is a clear indicator of heavy feeding activity by millipede populations in the area.

Damaged tubers often exhibit deep cavities accompanied by soft, decaying tissue, which gives off a distinct odor due to the colonization by opportunistic bacteria and fungi.

Observing them on the soil surface at night or after a heavy watering event provides direct evidence of their activity and helps in estimating the scale of the infestation.

Effective management relies on cultural practices such as removing decaying plant debris and organic mulch that serve as habitats for these millipedes, especially near vegetable beds.

Managing soil moisture is critical; ensuring proper drainage and avoiding excessive surface saturation can create a drier environment that is less hospitable for the millipedes to thrive.

Mechanical trapping using sliced potatoes or other moist vegetables buried just below the soil surface can be an effective non-toxic method to reduce populations in small gardens.

Chemical control can be achieved through the application of soil insecticides at planting, but this must be done following local regulations and guidelines to ensure safety for the crops and the environment.

Biological control methods involving entomopathogenic fungi offer a sustainable way to suppress millipede numbers while maintaining soil health and preventing potential chemical residues in the harvest.