Identification and Management Strategies for Cutworms as Pests in Field Corn


Cutworms are sporadic but serious early-season pests of corn in the United States. Several species of cutworm can feed on a broad range of plants, including vegetables, turf, field crops, and numerous weeds.1 Only limited research has been conducted on cutworms in recent decades in field corn other than on efficacy of transgenic hybrids expressing Bacillus thuringiensis (Bt) toxins.2,3 Although limited data are available from the southeastern United States, the insect remains an issue that can occasionally cause significant damage in the region. The purpose of this article is to provide for growers, consultants, and other agricultural professionals background information on cutworms, describe their injury to corn, and discuss management strategies.


A black cutworm moth.

Figure 1. Black cutworm, Agrotis ipsilon, moth. Image credit: Mark Dreiling,

Cutworms refer to the larval stage of several moth species from the Noctuidae family. While more than one species of cutworm can be found in corn, the black cutworm, Agrotis ipsilon, is the most common and will be the focus of this article. Other less common species include the claybacked cutworm, Agrotis gladiaria, and the dingy cutworm, Feltia ducens. Black cutworm adults are moths with a wingspan of 36-55 mm.1 Wings are mainly dark in color and have a lighter tip with “dagger-like” markings (figure 1). Globular white eggs (0.43-0.50 mm in height and 0.55-0.58 mm in width) are laid singly or in masses of up to 30 eggs.4

Larvae generally have six or seven developmental stages or instars, with larval size ranging from 3 mm for first instars to 45 mm for late instars.4 Color can range from pale grey to black, with a greasy looking texture with a granular appearance due to the presence of convex skin granules (figure 2). Fully grown larvae burrow into the ground to form a cocoon or pupa, which is dark brown and up to 2.2 cm in length.4

Two pictures of black cutworm larva on sticks and grass.

Figure 2. Black cutworm, Agrotis ipsilon, larva. Image credit: Roger Schmidt (left) and John Capinera (right),

Life Cycle

Although data are sparse from the southeastern United States, the insect does not overwinter in much of the Midwest,5 with wind mediated migration occurring from overwintering sites located in more southern regions.6 While winter survival as a larva has been reported in south Florida, it is likely that the insect overwinters in the soil as a pupa in much of the southeastern United States below 38 degrees latitude.6 Emergence occurs from March to May, with up to four overlapping generations in the United States.4 Moths lay eggs on plant hosts or crop residues on leaves and stems near the ground, with eggs hatching in three to five days.7 Larval development can last twenty-four to forty-seven days, depending on host plant and environmental conditions.8 After the fourth instar, larvae spend more time in the daytime in the soil, with feeding on plants during the night.7 Mature larvae dig into the soil to form a pupa, which can last ten to twenty days at a depth of 3 to 12 cm.1

Injury to Corn

A black cutworm larva next to a broken corn plant on the ground.

Figure 3. Black cutworm, Agrotis ipsilon, larva, and a severed corn plant. Image credit: W.M. Hantsbarger,

Until it reaches the 4th instar, the black cutworm is initially a leaf feeder,9 which does not impact the yield of corn.10 After reaching the 4th instar, more severe damage can occur due to larval feeding that can sever young corn plants close to the soil surface (figure 3). The susceptibility of corn varies with plant stage, as larvae are unable to significantly damage corn plants once they reach the 4th or 5th leaf stage.11 In addition, corn plants that are injured above their growing point can generally recover and contribute to yield.10,12 Corn plants cut below their growing point generally die.10,12 Later planted corn is also potentially more susceptible to cutworm injury in more northern areas in the United States.13


Scouting and Economic Thresholds

Scouting should begin from emergence until corn is in the 4th or 5th leaf stage. At five locations in a field, twenty plants in a row should be examined to record the number of plants that are cut, have wilting leaves, or have signs of leaf feeding.14 Larvae should also be sampled by examining the soil surface around damaged plants as well as in the soil by digging around a damaged plant. In the Midwest, thresholds of 2% to 3% for small larvae and 5% for larger larvae have been recommended.15 In Georgia, a threshold of 10% plants cut and larvae present is recommended for making management decisions.16

Chemical Control

Insecticides can be effective in managing cutworms in corn either proactively or as a rescue treatment. Proactive use of insecticides can involve the use of seed treatments, at-plant applications as a band (i.e., applying over the closed crop row only and not over the interrow) or T-band (i.e., applying over the open furrow only and not over the interrow), or in-furrow applications.15 Neonicotinoid insecticide seed treatments (clothianidin or thiamethoxam) are only moderately effective at low rates, and higher rates are needed to achieve adequate level of cutworm control (table 2).16 Seed treatments with chlorantraniliprole also provide excellent levels of control.16 Foliar applications can be effective16 when economic thresholds are reached. When herbicides are used to terminate cover crops prior to planting, a pyrethroid insecticide can be tank mixed in a broadcast application.16 Growers should use their own experience and field history when considering the need for intervention.17

Table 1. Insecticide seed treatments for black cutworm control (David Buntin, University of Georgia).16

Insecticide and rate1 Active ingredient Efficacy for black cutworm2
Poncho 250 (0.125 mg AI per seed) Clothianidin P-F
Poncho 500 (0.5 mg AI per seed) Clothianidin P-F
Poncho 1250 (1.25 mg AI per seed) Clothianidin F-G
Cruiser 250 0.125 mg AI per seed) Thiamethoxam P
Cruiser 500 (0.5 mg AI per seed) Thiamethoxam P
Cruiser 1250 (1.25 mg AI per seed) Thiamethoxam F
Cruiser 250 + Lumivia 250 (0.25 mg of each AI per seed) Thiamethoxam + chlorantraniliprole E

1 AI = active ingredient; 2 E = excellent, VG = very good, G = good, F = fair, P = poor.

Cultural Control

Winter annual weeds and perennial weeds have been associated with increased cutworm damage in corn, as females can lay eggs on weeds in and around corn fields prior to planting.18 In addition, management of weeds using tillage or herbicides close to planting can lead to increased damage in corn, as populations of cutworms that were feeding on weeds will move to corn.19 Research has suggested that management of weeds should occur more than a week prior to planting to encourage larval dispersal and/or mortality prior to emergence of corn.19 Corn planted using conservation tillage can be at a greater risk of damage than when using conventional tillage due to increased crop and weed residue.20 However, tillage can also be detrimental to predators (see section below), which can counteract the benefits of removing plant residues with tillage.21 While most management recommendations underline the value of tillage in reducing risk of damage from cutworms, it is important to note that cultural practices such as tillage can affect pest dynamics in multiple ways.

Biological Control

Naturally occurring biological control agents, including predators and parasitoids, can significantly reduce the amount of feeding by cutworms in corn. Ground beetles in the family Carabidae are common predators of soil and ground-dwelling pest species, including cutworms.22 Conventional tillage can reduce the number of ground-dwelling predators in the field, in addition to increasing the rate of cutworms clipping plants.21 Cutworms can also be parasitized by Meteorus leviventris and reduce its feeding by up to 50%.23 Entomopathenogenic nematodes (i.e., nematode species that infect insects) such as Steinernema feltiae can also be applied in commercial formulations as baits or aqueous solutions and have been shown to reduce cutworm feeding on corn by up to 50%.24 To minimize impacts on natural enemies, insecticides should be used only if absolutely needed.

Transgenic Bt Corn

Transgenic corn hybrids that express toxins produced by Bacillus thuringiensis (Bt corn) can help to suppress or control cutworms. Bt corn was first commercialized in 1995 primarily to manage the European corn borer. These initial Bt products produced a single toxin (Cry1Ab), which was not effective for control of black cutworm.25 The release of a new Bt trait in 2003 that expressed Cry1F expanded the spectrum of activity of insect pests controlled, which included the black cutworm.26 The efficacies of commercial Bt corn traits for black cutworm control in field corn are listed in table 2. Other Bt traits available for below-ground pests (rootworms) are not listed in this table. Bt products with a blended refuge or refuge-in-a-bag (RIB) are also not listed; these products are a mix of non-Bt and Bt seed in the same bag, which is not allowed as an insect resistance management strategy in southern cotton-growing areas of the United States.27

Table 2. Bt corn product efficacy for black cutworm.

Trade name Bt toxins Efficacy for black cutworm
Agrisure Artesian 3010A Cry1Ab P
Agrisure GT/CB/LL Cry1Ab P
Agrisure 3000 GT, Agrisure Artesian 3011A Cry1Ab, mCry3A3 P
Agrisure Viptera 3110 Vip3Aa20, Cry1Ab G
Agrisure Viptera 3111 Vip3Aa20, Cry1Ab, mCry3A3 G
Agrisure Viptera 3220 Vip3Aa20, Cry1Ab, Cry1F VG
Herculex I Cry1F G
Optimum Intrasect Cry1F, Cry1Ab G
Optimum Intrasect XTRA Cry1F, Cry1Ab, Cry34Ab1/Cry35Ab13 G
Optimum Leptra Cry1F, Cry1Ab, Vip3Aa20 VG
YieldGard Corn Borer Cry1Ab P
YieldGard VT Triple Cry1Ab, Cry3Bb13 P
Genuity VT Double PRO Cry1A.105, Cry2Ab2 P
Genuity VT Triple PRO Cry1A.105, Cry2Ab2, Cry3Bb13 P
Powercore Cry1A.105, Cry2Ab2, Cry1F G
Smartstax or Genuity SmartStax Cry1A.105, Cry2Ab2, Cry1F, Cry3Bb13, Cry34Ab1/Cry35Ab13 G
Trecepta Cry1A.105, Cry2Ab2, Vip3Aa20 VG

1 E = excellent, VG = very good, G = good, F = fair, P = poor. Excellent usually means better than 95 percent control. Poor means less than about 30% control. 2 See Insect Resistance Management (IRM) documentation from the seed companies for additional details. 3 Indicates a toxin for rootworm control. Adapted from D. Buntin and K. Flanders, 2014, Bt Corn Products for the Southeastern United States. Based on input from entomologists attending the annual National Cotton States Arthropod Pest Management Working Group meeting.


Cutworms are sporadic pests of field corn that can occasionally be severe pests. Fields at high risk of cutworm injury are often characterized by heavy weed presence in and around fields. Practices to manage weeds should be conducted at least one week prior to planting. Insecticides and transgenic Bt traits can help to reduce the risk of cutworm damage in corn.

References Cited

  1. Edde, PA. Arthropod pests of tobacco (Nicotiana tabacum L.), p. 2–73. In: Field crop arthropod pests of economic importance. Academic Press, Elsevier, New York.
  2. Pilcher CD, Rice ME, Obrycki JJ, Lewis LC. Field and laboratory evaluations of transgenic Bacillus thuringiensis corn on secondary lepidopteran pests (Lepidoptera: Noctuidae). Journal of Economic Entomology. 1997 Apr;90(2):669–678.
  3. Kullik SA, Sears MK, Schaafsma AW. Sublethal effects of Cry 1F Bt corn and clothianidin on black cutworm (Lepidoptera: Noctuidae) larval development. Journal of Economic Entomology. 2011 Apr;104(2):484–493.
  4. Crumb SE. Tobacco cutworms. Washington (DC): US Department of Agriculture; 1929 May.
  5. Story RN, Keaster AJ. The overwintering biology of the black cutworm, Agrotis ipsilon, in field cages (Lepidoptera: Noctuidae). Journal of the Kansas Entomological Society. 1982 Jul;55(3):621–624.
  6. Showers WB, Whitford F, Smelser RB, Keaster AJ, Robinson JF, Lopez JD, Taylor SE. Direct evidence for meteorologically driven long‐range dispersal of an economically important moth. Ecology. 1989 Aug;70(4):987–992.
  7. Abdel‐Gawaad AA, El‐Shazli AY. Studies on the common cutworm Agrotis ypsilon Rott: I. Life cycle and habits. Zeitschrift für Angewandte Entomologie1 1971 Jan;68(1–4):409–412.
  8. Busching MK, Turpin FT. Survival and development of black cutworm (Agrotis ipsilon) larvae on various species of crop plants and weeds. Environmental Entomology. 1977 Feb;6(1):63–65.
  9. Archer TL, Musick GJ. Cutting potential of the black cutworm on field corn. Journal of Economic Entomology. 1977 Dec;70(6):745–747.
  10. Levine E, Clement SL, Rubink WL, McCartney DA. Regrowth of corn seedlings after injury at different growth stages by black cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae) larvae. Journal of Economic Entomology. 1983 Apr; 6(2):389–391.
  11. Clement SL, McCartney DA. Black cutworm (Lepidoptera: Noctuidae): Measurement of larval feeding parameters on field corn in the greenhouse. Journal of Economic Entomology. 1982 Dec;75(6):1005–1008.
  12. Showers WB, Sechriest RE, Turpin FT, Mayo ZB, Szatmari-Goodman G. Simulated black cutworm damage to seedling corn. Journal of Economic Entomology. 1979 Jun;72(3):432–436.
  13. Krupke C, Obermeyer J. 2011. Other cutworms, too early for black cutworm. Lafayette (IN): Purdue Cooperative Extension Service; 2011 May 6 [accessed 2023 Feb 14]. Pest & Crop Newsletter, Issue 5. (
  14. Bessin R. Cutworm management in corn. Lexington (KY): University of Kentucky Cooperative Extension Service; 1997. ENT-59.
  15. Ostlie K. Black cutworm. Minneapolis (MN): University of Minnesota Extension; 2021.
  16. Buntin GD. Insect control in field corn. In: Bryant C, Ethredge R, editors. Georgia corn production guide. Athens (GA): Georgia Agricultural Extension Service. Miscellaneous Publications. p. 38–53.
  17. Buntin GD. Corn insect Control. In: Georgia pest management handbook. Athens (GA): University of Georgia Extension; 2023. Special Bulletin 28. p. 51–61.
  18. Sherrod DW, Shaw JT, Luckmann WH. Concepts on black cutworm field biology in Illinois. Environmental Entomology. 1979 Apr;8(2):191–195.
  19. Showers WB, Von Kaster L, Sappington TW, Mulder PG, Whitford F. Development and behavior of black cutworm (Lepidoptera: Noctuidae) populations before and after corn emergence. Journal of Economic Entomology. 1985 Jun;78(3):588–594.
  20. Willson HR, Eisley JB. Effects of tillage and prior crop on the incidence of five key pests on Ohio corn. Journal of Economic Entomology. 1992 Jun;85(3):853–859.
  21. Brust GE, Stinner BR, McCartney DA. Tillage and soil insecticide effects on predator-black cutworm (Lepidoptera: Noctuidae) interaction in corn agroecosystems. Journal of Economic Entomology. 1985 Dec;78(6):1389–1392.
  22. Lund RD, Turpin FT. Serological investigation of black cutworm larval consumption by ground beetles. Annals of the Entomological Society of America. 1977. May;60(3):322–324.
  23. Schoenbohm RB, Turpin FT. Effect of parasitism by Meteorus leviventris on corn foliage consumption and corn seedling cutting by the black cutworm. Journal of Economic Entomology. 1977;70(4):457–459.
  24. Capinera JL, Pelissier D, Menout GS, Epsky ND. Control of black cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae), with entomogenous nematodes (Nematoda: Steinernematidae, Heterorhabditidae). Journal of Invertebrate Pathology. 1988 Nov;52(3):427–435.
  25. Pilcher CD, Rice ME, Obrycki JJ, Lewis LC. Field and laboratory evaluations of transgenic Bacillus thuringiensis corn on secondary lepidopteran pests (Lepidoptera: Noctuidae). Journal of Economic Entomology. 1997 Apr;90(2):669–678.
  26. Kullik SA, Sears MK, Schaafsma AW. Sublethal effects of Cry 1F Bt corn and clothianidin on black cutworm (Lepidoptera: Noctuidae) larval development. Journal of Economic Entomology. 2011 Apr;104(2):484–493.
  27. Reay-Jones FPF. Managing insect pests in field corn using transgenic Bt technology. Land-Grant Press by Clemson University Cooperative Extension. 2021; LGP 1132.

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