Orthomorpha coarctata

Orthomorpha coarctata is a species of polydesmid millipede belonging to the family Paradoxosomatidae. Often referred to as a tropical millipede, it has successfully established itself in greenhouse environments and nurseries worldwide, adapting to artificial climates where it finds constant moisture and food sources.

This millipede is known for its preference for damp, organic-rich soil environments. In agricultural settings, it specifically attacks the root systems, seedlings, and lower stems of various horticultural and ornamental crops. Young plants are particularly vulnerable, as feeding damage to the roots can lead to immediate wilting and mortality.

The biology of the species is marked by high adaptability. These millipedes remain hidden during the day, emerging at night to feed. Their lifecycle involves a gradual metamorphosis where they add segments with each successive molt. In greenhouse conditions, they are capable of continuous reproduction, maintaining high population densities if left unmanaged.

Damage caused by Orthomorpha coarctata includes the chewing of tender root tissue and stems near the soil surface. These wounds serve as entry points for secondary pathogens, such as root rot fungi and bacteria, which significantly increase the total damage to the crop. The risk is highest in areas with poor drainage and excessive organic debris in the soil.

Effective control strategies focus on integrated pest management practices. These include:

• Reducing soil moisture through improved drainage.
• Sanitation, specifically removing decomposing organic matter from greenhouse floors.
• Application of specialized soil-applied insecticides registered for millipede control.
• Proper soil management and sterilization before planting new crops.