Turfgrass-Cutworm

Primarily
Black cutworm (Agrotis ipsilon)
Glassy cutworm (Apamea devastator)
Variegated cutworm (Peridroma saucia)
Winter cutworm (Noctua pronuba)

Pest description and crop damage Adult cutworms are medium to large moths but all damage is due to larval feeding. Larvae are typically 1 to 1.5 inches long. Winter cutworm have black dashes that run the length of the larvae, bordered by a cream-yellow line. Winter cutworm also have a tan head with 2 black arcs on the eyes. The black cutworm are light gray to almost black in color, with a greasy appearing texture and coarse granules of various size on the skin. The glassy cutworm larvae is glossy, semi-translucent with a greenish-white or grey body lacking body markings, and a prominent reddish-brown head. The variegated cutworm has a series of 4 to 7 small, yellow dorsal spots and the terminal (most posterior) body segment has a transverse yellow line and a black 'W', which is most evident on mature larvae. Winter cutworm and black cutworm are more common turfgrass pests than the glassy and variegated cutworm. Larval cutworm populations build as the summer progresses and damage typically occurs in the late fall or early winter when turfgrass growth slows, but larvae continue to feed on the turfgrass. Birds will also disrupt the turfgrass surface while feeding on the insects in the fall. Black cutworm feed on turfgrass maintained at a low height (greens and fairways) while winter cutworm feed on turfgrass in higher cut areas (lawns, sports fields, and golf course roughs).

Biology and life history Both winter cutworm and black cutworm overwinter as larvae and adults emerge throughout May and June. Eggs are laid on host plants, and hatch after a few days. Young larvae feed only on foliage, although mature larvae develop a subterranean habit and may cut off plants at the surface and feed on them in their burrows. If the lawn has been aerated, cutworms may be found in the late summer and fall in these holes and damage is apparent around them.

Scouting and Thresholds Scouting for larvae should begin in the fall months (September and October) prior to the onset of cold weather. The action threshold for well-maintained turfgrass is 4 larvae per sq ft. Scout using a tablespoon of lemon scented dish soap in a five-gallon bucket of water. Apply the mixture and wait for 5 minutes. Larvae will emerge from the soil and thatch trying to escape the dish soap application.

Management-biological control

Birds can often assist in control since they will pluck them from the turf, although this in itself may be damaging to turf.

  • Bacillus thuringiensis-Some formulations are OMRI-listed for organic use.
  • beneficial nematodes-Read label carefully for application procedures, timing and appropriate soil temperatures for best efficacy.

Management-Chemical control: HOME USE

Do not permit children or pets on the treated turfgrass until it has been watered to wash the insecticide into the turf and the grass is completely dry. Most insecticides are toxic to bees exposed to direct treatment or to residues on blooming weeds/ flowers in lawns: mow and remove clippings prior to applying insecticides.

  • azadirachtin (as a mix with pyrethrins)-Some formulations are OMRI-listed for organic use.
  • bifenthrin (often as a mix with other active ingredients)
  • carbaryl
  • chlorantranilprole
  • clothianidin (as a mix with pyriproxyfen)
  • cyfluthrin
  • fenvalerate
  • gamma-cyhalothrin
  • imidacloprid
  • indoxacarb
  • lambda-cyhalothrin
  • permethrin
  • plant essential oils (clove, garlic, thyme, etc.)-Some have demonstrated efficacy against Lepidopteran larvae. Some formulations are OMRI-listed for organic use.
  • pyrethrins-Some formulations are OMRI-listed for organic use.
  • spinosad (as a mix with insecticidal soap)-Some formulations are OMRI-listed for organic use.

Management-Chemical control: COMMERCIAL USE

Do not permit children or pets on the treated turfgrass until it has been watered to wash the insecticide into the turf and the grass is completely dry. Most insecticides are toxic to bees exposed to direct treatment or to residues on blooming weeds/ flowers in lawns: mow and remove clippings prior to applying insecticides.

  • acephate (Orthene Turf Tree & Orn. WSP)
  • azadiractin (Azasol, Azatin, Azaguard Botanical Insecticide/Nematicide, Neemix 4.5 IGR)-some formulations- OMRI-listed for organic use.
  • beta-cyfluthrin (Tempo SC Ultra Insecticide,)
  • bifenthrin (S, Select Insecticide, multiple label names) at 0.05 to 0.1 lb ai/A. PHI 30 days. REI 12 hr. Bifenthrin is highly toxic to bees and other pollinators exposed to direct treatment or residues on blooming crops or weeds. Do not apply bifenthrin or allow it to drift to blooming crops or weeds if bees or other pollinating insects are foraging in the treatment area. Extremely toxic to fish and aquatic invertebrates. Do not apply if rain is expected within 24 hr or whatever time is necessary for product to dry.
  • bifenthrin + imidacloprid (Allectus G Insecticide)-Note: Neonicotinoid pesticides have been banned from use on public properties in some towns and counties (check with local authorities).
  • capsaicin + allyl isothiocyanate (Dazitol Concentrate)
  • carbaryl (Sevin Brand RP4 Carbaryl, Lebanon Sevin 7G Granular Insect Control, Sevin SL Carbaryl Insecticide)
  • chlorantraniliprole (Acelepryn Insecticide, Acelepryn G Insecticide)
  • clothianidin (Arena 0.25G Insecticide, Arena, 50 WG Insecticide, Arena 50 WDG Insecticide)-Apply as soon as overwintering adults are seen in the spring. Note: Neonicotinoid pesticides have been banned from use on public properties in some towns and counties (check with local authorities).
  • clothianidin + bifenthrin (Aloft GC G Insecticide, Aloft GC SC Insecticide, Aloft LC G Insecticide, Aloft LC SC Insecticide)-Restricted use.
  • cyfluthrin (Tempo 20WP Golf Course Insecticide in WSP, Tempo 20 WP Insecticide)
  • deltamethrin (Deltagard G Insecticide, D-Fense SC Insecticide, Suspend SC Insecticide)-For adults.
  • dinotefuran (Zylam)-Note: Neonicotinoid pesticides have been banned from use on public properties in some towns and counties (check with local authorities).
  • esfenvalerate + prallethrin + piperonyl butoxide (Onslaught FastCap Spider and Scorpion Insecticide)
  • gamma-cyhalothrin (Scion Insecticide, Optimate CS)
  • imidacloprid (Adonis 2F Insect Conc., AmTide Imidacloprid, Avatar PLX Insecticide, Lesco Bandit 0.5G Granular Insecticide, Lesco Bandit 2F Insecticide, Lesco Bandit 75 WSP Insecticide, Malice 0.5G, Malice 2F Insecticide, Malice 75WSP, Mallet 0.5G Insecticide, Mallet 2F Insecticide, Mallet 2F T&O Insecticide Mallet 75 WSP Insecticide, Mallet 7.1% PF Insecticide, Merit 0.5G Insecticide, Merit 2F Insecticide, Merit 75WP Insecticide, Merti 75WSP Insecticide, Midash 2SC T&O, Prokoz Zenith 0.5G Insecticide, Prokoz Zenith 2F Insecticide, Quali-Pro Imidacloprid 0.5G, Quali-Pro Imidacloprid2F T&O, Quali-Pro Imidacloprid 75 WSB Insecticide in WSP)-For larvae. Note: Neonicotinoid pesticides have been banned from use on public properties in some towns and counties (check with local authorities).
  • indoxacarb (DuPont Provaunt Insecticide, Provaunt Insecticide)-For larvae.
  • mint oil, geraniol + oil of rosemary (Keyplex Ecotrol Plus Insecticide/Miticide, Essentria IC3 Insecticide)-OMRI-listed for organic use.
  • spinosad A&D (Conserve SC Turf & Ornamental Insect Control)-For larvae. Some formulations are OMRI-listed for organic use.
  • thiamethoxam (Meridian 0.33G Insecticide, Meridian 25WG Insecticide, Flagship 25WG Insecticide)-Note: Neonicotinoid pesticides have been banned from use on public properties in some towns and counties (check with local authorities).
  • trichlorfon (Dylox 6.2 Granular, Dylox 420 SL Turf & Ornamental)-For larvae.

Related Links