Overview: A Pest With a Wide Reach
The invasive Portuguese millipede, a scaly, dark-bodied pest, has become a growing concern for residents on Wellington’s south coast and beyond. Initially detected in localized pockets, reports indicate the species has begun to spread to neighboring regions as warmer seasons extend its activity. Entomologists warn that this is not merely a nuisance; the millipede’s spread can disrupt local ecosystems, damage gardens, and pose challenges for households dealing with repeated indoor sightings.
Where It’s Spreading
Recent observations suggest the invader has moved beyond Wellington, reaching adjacent coastal communities and peri-urban areas. The millipede’s life cycle, moisture preferences, and ability to hitch rides in footwear, bags, and transit goods contribute to its rapid expansion. Experts note that damp environments, leaf litter, and mulch beds create ideal shelter for breeding and concealment, increasing the likelihood of accidental transport into homes and vehicles.
Why This Species Is A Concern
The Portuguese millipede is not native to New Zealand, and its introduction disrupts local arthropod communities. It outcompetes some native invertebrates for shelter and food, and its presence can affect soil health and plant vitality. While millipedes generally rely on detritus for nutrition, large populations can lead to higher soil turnover and increased predation pressure on smaller soil organisms. Public health concerns are typically low, but the sheer density of sightings—especially inside living spaces—fuels anxiety and raises questions about home safety and cleanliness.
Behavior and Habits
These millipedes are most active in damp, shaded areas. They seek refuge under stones, garden debris, and in basements or garages when weather turns unsuitable. Movement indoors often occurs when doors or windows are left ajar, or when individuals brush clothing and footwear after outdoor activities. They do not bite or sting, but their many legs can deliver a ticklish but harmless sensation. The real challenge lies in detection and eradication: a single female can lay eggs in hidden crevices, leading to sudden population surges if conditions remain favorable.
What Residents Can Do Now
Controlling the Portuguese millipede requires a combination of prevention, sanitation, and targeted treatment. Residents on Wellington’s south coast—and now other affected areas—should:
- Seal entry points: Patches around doors, windows, and utility gaps should be checked and sealed to prevent entry during warm, humid periods.
- Reduce indoor attractants: Clear clutter, store belongings in sealed containers, and reduce moisture buildup in basements and bathrooms.
- Manage outdoor habitats: Regularly remove leaf litter, decaying wood, and dense ground cover near the home, and ensure proper drainage to avoid damp microhabitats.
- Inspect footwear and bags: Check shoes and travel bags before bringing them indoors after outdoor activities, especially in areas with high millipede activity.
- Use safe repellents and targeted barriers: If advised by local authorities, employ approved barriers or non-toxic repellents around entry points and perimeters.
- Seek professional help for outbreaks: If you notice persistent, large populations, contact local extension services or pest control professionals who can identify species and tailor treatment plans without harming non-target organisms.
Public Health and Community Response
Local councils and environmental agencies are monitoring the situation and sharing guidance on best practices for preventing spread. Community education campaigns emphasize early detection, proper disposal of infested plant material, and reporting sightings to authorities. While the Portuguese millipede is not a major vector for disease, its nuisance factor affects daily life and property values, making coordinated action essential.
Looking Ahead
As climate patterns shift, many invasive species experience shifts in range. The spread of the Portuguese millipede beyond Wellington is a reminder that vigilance, rapid reporting, and collaboration between residents and scientists are crucial to managing pests effectively. By staying informed and adopting practical prevention steps, communities can reduce new infestations, protect gardens, and minimize indoor encounters.
Key Takeaways for Homeowners
- Be vigilant for ticks, nibbles, or unusual movement in footwear and bedding.
- Maintain dry, clutter-free indoor spaces and address moisture sources.
- Coordinate with local authorities for verification and treatment guidance.
