Clark County logo   Clark County Washington title  
Links to finding county services
Search the Web site
Clark County home page A to Z index Find it Links to other sites News releases Contact us

Environmental Services

Recycling, Garbage & Hazardous Waste

Waste Reduction

Garbage Collection & Disposal

Recycling Collection & Disposal

Recycling A-Z Index

Solid Waste Advisory Commission

Household Hazardous Waste (HHW)

Small Quantity Generators (SQG)

Yard Debris/Composting

School Programs

Naturally Beautiful





Recycle A to Z

alternatives to pesticides - bugs/pests - symphylans


Actual size: 1/20” – 1/4”

Symphylans, sometimes called garden centipedes, are found in rich, moist soils. Symphylans are about 1/4” long at their largest, white, have 12 pairs of legs, and feed on plant roots. Note that true centipedes have 15 pairs of legs and eat other insects, so correct identification is very important.  Symphylans are usually brought into a landscape in manure or compost and thrive in very moist soils high in organic matter. They feed on the roots of many different plants and, in high numbers, can kill young starts. Older plants often can outgrow the damage as long as the have adequate water. Susceptible plants include tomatoes, lettuce, sugar beets, chrysanthemum, asparagus, beans, brassicas, celery, cucumber, parsley, peas, peppers, potatoes and strawberries.  Symphylans are especially difficult to get rid of once they have become established in a garden. None of the following suggestions are foolproof, but, when used together, can probably reduce their numbers.

The best bet for symphylan control is to not get them in the first place.  If you are bringing in manure to add to the garden, look it over with a magnifying glass for symphylans before applying it. If your soil tends to be wet, be careful not to over apply organic matter, don’t use organic matter as your only source of fertilizer or consider moving the garden to a drier location. If they inhabit your compost pile, eliminate that pile and resume composting on a plastic sheet or concrete slab. Symphylans tend to occur in spots in the garden, so crop rotation into non-susceptible plants may help.

Biological control
Beneficial nematodes - Beneficial nematodes may help to control symphylans. Be sure to follow label directions.

Physical control
Flood - If the site is level, you can try flooding the area for several days in winter to try and drown symphylans.
Cover - Or, cover the site with plastic on a sunny, warm day to heat the site and kill the pests.
Rototill - Symphylans are fairly delicate creatures, and cultivation will also help reduce their numbers. Rototill in the spring and fall and hand cultivate round plants during the season to stir up the soil and destroy symphylans.



Back to A-Z list