Garden symphylan

Garden symphylans are small (1/8 inch), pale, centipede-like arthropods found in moist soil around strawberry plants and occasionally woody ornamentals like arbutus in Western Washington. You notice damage to roots, underground stems, and emerging seedlings; plants appear stunted or wilt despite adequate moisture. Symphylans prefer cool, wet soils and are most active during spring and fall in the Puget Sound region. Dig into soil to find them.

Reduce soil moisture by improving drainage and avoiding frequent, light irrigation that keeps soil consistently wet. Allow soil to dry moderately between waterings. Remove organic debris from plant crowns. For severe infestations in high-value plantings, soil drenches with spinosad can suppress populations. Cultural management of soil moisture is the primary control method.