Turf nematodes
Root-feeding nematodes, including Southern Sting (Ibipora lolii).
Plant-parasitic nematodes feed on turf roots and can leave irregular areas weak, yellow or thin. These symptoms overlap with moisture stress and root diseases, so a photograph cannot confirm the cause.
Photo: Syngenta Turf Australia · Full photo ↗
What to look for
- Uneven yellowing, thinning or wilting that persists despite routine lawn care.
- Poor growth above roots that are short or stubby, with fewer fine feeder roots.
- Root swellings in some nematode problems; their absence does not exclude other species.
Check the grass and site
Warm- and cool-season turf can be affected. Australian Southern Sting hosts include couch, kikuyu, bentgrass and perennial ryegrass; the nematode species and site conditions influence damage.
Confirm it before you treat it
Contact a turf diagnostic laboratory for its soil and root sampling instructions. Request identification and population counts, then assess the result alongside root condition, turf performance and other possible causes. Counts alone are not a complete diagnosis.
What to do next
- Reduce mowing and traffic stress while maintaining suitable moisture and balanced nutrition; avoid excessive nitrogen.
- Limit movement of potentially infested soil and turf, and work on healthy areas before affected sites.
- Use the diagnosis to plan management and repeat root-health checks and counts where advised. A labelled product must suit the confirmed pest, site and application equipment.
Conditions matter more than dates.
Southern Sting is associated with sandy, well-irrigated soils. Damage to roots reduces tolerance of other stresses, and nematodes can move between sites with soil, turf and equipment.
Does finding nematodes mean treatment is needed?
No. Many soil nematodes are not plant parasites. Identification, relevant counts and the condition of the turf determine whether a management response is justified.
Compare similar problems
Localised dry patch
A watered lawn can still have dry roots in isolated areas.
Identify & find a solution ↗Photo: Paden Johnson / U of A · CC BY-SA 2.0
Heat & drought stress
Check the roots and irrigation before treating browning as disease.
Identify & find a solution ↗Photo: Famartin · CC BY-SA 4.0. Resized; no other edits.
Pythium blight
Greasy, matted patches that can move quickly in wet, hot conditions.
Identify & find a solution ↗Reviewed 18 October 2026 · Turfmate. Identification guidance is not a laboratory diagnosis or a spray calendar.
Technical sources & image credits
- Microscope views of nematodes. This reference shows the microscopic pests; identifying damaging populations requires laboratory assessment. Photo: Syngenta Turf Australia · Syngenta content licence.
- Pythium blight following low ground and surface water flow. Photo: Pete Dernoeden, Ph.D / Syngenta GreenCast · Syngenta content licence.
Syngenta photographs are reproduced in full with attribution. Source grass species and settings are identified where supplied; photographs support identification and do not replace diagnosis.
- Syngenta Australia — Managing the Challenge of Plant Parasitic Nematodes in Turf
- Agriculture Victoria — Sting nematode on turfgrass
- Turf Culture — Thumper Australian label
A Turfmate product link does not imply endorsement by a photographer or source.