Tiny white bugs in the soil

Most of what moves on the surface of damp potting compost is harmless. Springtails, the commonest, rarely damage plants and are a sign of overwatering; soil mites mostly feed on fungi and decaying matter. The ones worth acting on are fungus gnats, whose larvae feed on root hairs and harm seedlings and young plants, and, below the surface, root aphids and root mealybugs. For springtails and fungus gnats, let the top of the compost dry between waterings.

1. SpringtailsCollembolaMost likelyHarmlessSpecks that spring away when you disturb the surface; the jump is the giveaway. They feed mainly on fungi, algae and decaying matter and rarely damage plants, though some species chew seedlings. Numbers drop when the compost is allowed to dry between waterings.Full pest profile →
2. Soil mitesOribatida and othersAlso commonHarmlessSlow-moving specks that crawl rather than jump, unlike springtails, and wander loose through the compost rather than clustering on the roots like root aphids. Most feed on fungi and decaying matter, or hunt other tiny animals.Full pest profile →
3. Fungus gnatBradysia spp.Also commonWhitish-to-clear, legless larvae with a shiny black head, inside the top few centimetres of compost. The adults are the small dark flies that rise when you move the pot. The larvae feed on root hairs and fungi, and hurt seedlings, cuttings and young plants most.Full pest profile →
4. Root aphidsRhopalosiphum rufiabdominale and othersLess oftenFound on the roots rather than roaming the surface: small yellow, green or brown aphids clustered under white, powdery wax that builds up on the roots, with a plant that wilts and stunts for no visible reason. Found when the pot comes off.Full pest profile →
5. Root mealybugsRhizoecus spp.Less oftenSlow, oval, white and waxy, with no filaments around the edge, living in crevices of the compost and in chambers at the outer edge of the root ball, where it meets the pot. The plant stunts and yellows.Full pest profile →