Garden Centipedes (Scutigerella immaculata)

If you dig into moist soil or move a flowerpot and see a tiny, white, fast-moving creature with many legs, you’ve probably met the garden centipede (Scutigerella immaculata).
Despite the name, it’s not a true centipede at all. It belongs to a different group called Symphyla, a lesser-known class of soil-dwelling arthropods.

In my years doing pest inspections in greenhouses and gardens, I’ve often found these small creatures crawling among plant roots. Most homeowners think they’re baby centipedes — but these garden symphylans, as they’re correctly called, are something else entirely.

While they don’t bite or carry disease, in large numbers they can damage root systems, stunt seedlings, and reduce crop yields. Understanding what they are and how they live is the key to managing them properly.

Identification

The garden centipede (Scutigerella immaculata) is tiny, soft-bodied, and almost invisible to the naked eye in soil. Here’s how to identify it:

• Scientific name: Scutigerella immaculata

• Common names: Garden centipede, garden symphylan, white soil centipede

• Length: 2–8 mm (less than 1/3 inch)

• Color: White to translucent

• Body shape: Elongated and segmented, flexible like a worm

• Legs: 12 pairs (unlike true centipedes, which have 15+ pairs)

• Antennae: Long and flexible

• Habitat: Moist soil, compost, under mulch, greenhouse beds

They’re most active in cool, humid soil layers, where they move rapidly between cracks. If you disturb the soil, they disappear instantly — fast enough to vanish before you focus your eyes.

One easy distinction: true centipedes (Chilopoda) are flattened predators with visible claws and darker bodies, while symphylans like S. immaculata are pale, wormlike decomposers that live completely underground.

Biology and Ecology

The garden centipede’s biology is perfectly adapted for life in the soil ecosystem.

Life cycle:

• Eggs are laid singly in soil, often near decaying roots or compost.

• Newly hatched juveniles have 6 pairs of legs, gaining more after each molt until they reach 12 pairs.

• They can live up to 1 year, continuously molting and reproducing under suitable humidity.

Habitat preference:

• Moist, well-aerated soils with high organic matter

• Neutral to slightly acidic pH

• Temperature between 10–25°C

Feeding habits:

• Feed on organic matter, fungi, root hairs, and tender roots.

• In low numbers, they help decompose organic waste and improve soil texture.

• But when populations grow too large, they damage seedling roots, especially in greenhouses and vegetable gardens.

They’re most active at night and tend to migrate up and down the soil profile depending on moisture levels.

Global Distribution

Scutigerella immaculata is found on every continent except Antarctica.

• Europe: Common in garden soils, greenhouses, and plant nurseries.

• North America: A major pest in the Pacific Northwest (especially Oregon and California) in strawberry and vegetable crops.

• Asia: Reported in India, Japan, and Southeast Asia in sugarcane and ginger plantations.

• Australia and New Zealand: Present in cultivated soils and compost.

Because they prefer moist organic soil, they often thrive in human-managed environments — irrigation systems, greenhouse benches, and heavily mulched beds.

Risks and Damage

While garden centipedes are part of the natural soil fauna, they can cause significant damage when populations explode.

1. Plant damage

• Feed on root tips, root hairs, and seeds before or just after germination.

• Seedlings may appear stunted, wilted, or yellow.

• Damaged roots often show tiny brown feeding scars.

2. Crop impact

• Can reduce yield in carrots, lettuce, strawberries, beans, onions, potatoes, and many greenhouse crops.

• In hydroponic or nursery setups, they multiply fast due to stable humidity.

3. Hidden pest problem
Because they live below the surface, infestations are often misdiagnosed as fungal root rot or nutrient deficiency until soil examination confirms their presence.

Signs of Infestation

It’s rare to see them directly, but you can recognize an infestation by these symptoms:

• Uneven or patchy seedling growth

• Roots appearing chewed or missing fine root hairs

• Sudden wilting during cool, damp periods

• Crawling white arthropods visible in moist soil when disturbed

• Decline in greenhouse or nursery plants despite good watering and fertilization

A simple diagnostic test:

1. Take a shovel of moist soil, place it on a white tray, and shine a lamp overhead.

2. The symphylans will crawl to the surface within minutes.

3. If you count 10–20 per shovel of soil, population levels are high enough to cause economic damage.

Control Methods

Controlling Scutigerella immaculata is challenging — they reproduce fast, hide deep in the soil, and resist most surface treatments.
But with persistence and correct management, populations can be kept below damaging levels.

1. Cultural Control

• Reduce soil moisture: Improve drainage and avoid over-irrigation.

• Deep tillage: Occasionally turning the soil brings them to the surface, where they dry out or become prey to birds.

• Crop rotation: Alternate susceptible crops (lettuce, beans) with less affected ones (corn, onions).

• Avoid excessive organic composts: Limit fresh organic matter, which encourages breeding.

2. Physical Control

• Solarization: Cover soil with clear plastic during hot months for 3–4 weeks to kill eggs and nymphs.

• Soil flooding: Temporary flooding (in greenhouses) can drown some stages, though risky for roots.

• Traps: Potato slices placed in soil can attract them for monitoring or removal.

3. Biological Control

• Natural predators include predatory mites, rove beetles, and entomopathogenic fungi (Beauveria bassiana).

• In healthy soil ecosystems, predator activity naturally suppresses populations.

4. Chemical Control

Chemical options are limited. Traditional insecticides often fail because symphylans live deep underground.
However:

• Soil drenches containing pyrethroids or organophosphates may help in severe infestations — only by licensed professionals.

• Soil fumigation (e.g., chloropicrin) is used commercially but is unsuitable for home use.
  Always combine chemicals with moisture control and soil management for long-term results.

Advanced Approaches

Modern Integrated Pest Management (IPM) treats garden centipedes as an indicator species of soil health rather than a pest to be eliminated outright.
A few principles I recommend to my clients:

• Keep soil balanced — not too dry, not too rich in compost.

• Encourage predatory insects and beneficial nematodes.

• Avoid overuse of fertilizers and chemicals that disrupt soil life.

• Monitor populations seasonally, not just after damage appears.

In my experience, completely eradicating them is nearly impossible — but controlling conditions makes them harmless.

Cultural and Historical Context

Interestingly, Scutigerella immaculata was first described scientifically in the 19th century, when farmers in Europe noticed “tiny white worms” damaging root crops.
At the time, they were confused with maggots or millipedes, leading to many superstitions — some even blamed soil “spirits” for the withered plants.

Today, symphylans are recognized as a global agricultural pest, particularly in high-value organic systems, where chemical use is restricted.
Researchers continue to study their behavior because of their ancient evolutionary lineage — they may hold clues to how early arthropods adapted to soil life.

FAQ Section

1. What are garden centipedes?
They are small soil-dwelling arthropods (Scutigerella immaculata) that feed on organic matter and plant roots. Despite their name, they are not true centipedes.

2. Are garden centipedes harmful?
In small numbers, no. But in large populations, they can damage root systems and reduce crop yields.

3. How do I identify them?
Look for tiny, white, many-legged creatures moving quickly in moist soil — usually less than 8 mm long.

4. Do they bite humans?
No. They are harmless to people and pets.

5. What causes an infestation?
Overly moist soil, excessive compost, and a lack of predators create ideal breeding conditions.

6. How can I control them naturally?
Improve soil drainage, rotate crops, use potato traps, and encourage predatory soil insects.

7. Do pesticides work?
Most surface insecticides fail. Only professional-grade soil drenches or fumigation work in severe infestations.

8. Are garden centipedes beneficial?
Yes, when populations are low — they help break down organic matter and improve soil structure.