Turfmate field notes · Pests

Black cutworm

Agrotis ipsilon

Night-feeding caterpillars can damage leaves and young turf.

Black cutworm larva, pictured on soil beside a corn seedling.
Black cutworm larva, pictured on soil beside a corn seedling.
Photo: W. M. Hantsbarger, Bugwood.org · source · CC BY 3.0 US. Displayed at reduced size; card crops fit the layout.

What to look for

  • Caterpillars may curl up when disturbed.
  • Fresh damage occurs at leaf or stem level.
  • Larvae hide near the soil surface or in thatch between feeding periods.

Confirm it before you treat it

Look at dusk along the boundary of a damaged area. Small holes and clipped leaves can have several causes; locate the insect rather than treating the mark alone. The identification photo shows a larva beside a crop seedling, not a damaged lawn.

What to do next

  1. Collect a clear caterpillar photograph and note the size.
  2. Compare the damaged patch with healthy turf and check whether roots remain intact.
  3. Monitor newly established areas and close-cut turf carefully during active feeding periods.
Seasonal watch

Conditions matter more than dates.

Active caterpillar feeding and the vulnerability of the turf determine urgency. A fresh insect sample helps separate cutworm from other caterpillars.

Use the warmer growing season as a monitoring prompt, with checks driven by actual feeding. Local activity varies.

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Can I identify cutworm from a bare patch?

No. Find and photograph the larva. Chewed turf, disease and wear can overlap in appearance from a distance.

Inspect & compare

Recognise the pupal stage.

The lead photograph shows a caterpillar. This close-up shows the pupal stage of the same species, Agrotis ipsilon. Mature cutworm larvae pupate in soil. A pupa is a life-cycle clue; look for active larvae and fresh feeding to assess turf damage.

Close-up of the reddish-brown pupal stage of black cutworm, Agrotis ipsilon, against a black background
Black cutworm pupa. This is a life-cycle identification photograph, not a caterpillar or turf-damage photograph.
Photo: USGS Bee Inventory and Monitoring Lab / Sam Droege · CC BY 2.0. Resized from the original; no other edits.
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Keep investigating

Similar problems. Different solutions.

Reviewed 10 October 2026 · Turfmate. Seasonal windows are indicative planning guidance, not measured outbreak or prevalence data.

Technical sources & image credits

Photos support identification and may have been taken outside Australia. Appearance varies with species, mowing and conditions. A Turfmate product link does not imply endorsement by a photographer or source.