Various species, including:
Armyworm (Pseudaletia unipuncta)
Army cutworm (Chorizagrotis auxillaris)
Black cutworm (Agrotis ipsilon)
Glassy cutworm (Apamea devastator)
[No common name] (Protagrotis obscura)
Pest description and crop damage Larvae are 1 to 2 inches in length at maturity. All, except glassy cutworm and Protagrotis obscura usually feed above ground on foliage after dark or during conditions of low light intensity. Larvae cause most damage to new seedlings, particularly if the previous crop was heavily infested and the larvae were not controlled.
Management-chemical control
- azadirachtin (Aza-Direct, Atrevia 3% SL)-Aza-Direct at 0.012 to 0.030 lb ai/A; Atrevia 3% SL at 0.015 to 0.03 lb ai/A REI 4 hr. PHI 0 days. OMRI-listed for organic use.
- Bacillus thuringiensis (Xentari, Biobit, BT NOW, Javelin)-Xentari and Biobit at 0.5 to 2 lb product/A; BT NOW at 1 to 3.5 pt/A; Javelin at 0.25 to 1.5 lb product/A. PHI 0 days. REI 4 hr. Armyworms only. Add an appropriate spreader-sticker to enhance control. Most effective on small, actively feeding larvae. OMRI-listed for organic use.
- beta-cyfluthrin (Baythroid XL, Cryptoid XL, Sultrus) at 0.013 to 0.015 lb ai/A. PHI 0 days for grazing or hay. REI 12 hr. Do not exceed 0.089 lb ai/A per season. Retreatment interval 5 days.
- bifenthrin (Brigade 2EC, Discipline 2EC, Sniper, Bifenture EC, Discipline 2EC, Lancer 2EC) at 0.05 to 0.1 lb ai/A. PHI 30 days for forage and hay. REI 12 hr. Retreatment interval 14 days. Do not exceed 0.2 lb ai/A per year.
- carbaryl (Drexel Carbaryl 4L, Carbaryl 4L, Sevin XLR ) at 1 to 1.5 lb ai/A. PHI 14 days. REI 12 hr. Limit 2 treatments per year. Retreatment interval 14 days. Do not exceed 3 lb ai/A per year. Armyworms only.
- carbaryl (Sevin 5 Bait) at 1.5 lb ai/A. PHI 7 days for harvest or grazing. Limit 2 treatments per year. REI 12 hr. Retreatment interval 14 days.
- chlorantraniliprole (Coragen, Prevathon,, Shenzi 400SC, Vantacor, Plaid SC) at 0.045 to 0.098 lb ai/A for armyworms, and 0.065 to 0.098 lb ai/A for cutworms. Max rate of Prevathon is 0.067 lb ai/A for armyworms and 0.097 lb ai/A for cutworms. PHI 0 days. REI 4 hr. Retreatment interval 7 days. Do not exceed 0.2 lb ai/A or 4 applications per season.
- chlorantraniliprole/lambda-cyhalothrin (Besiege, Voliam Xpress) at 0.0391 to 0.0652 lb ai/A for chlorantraniliprole and 0.0195 to 0.0325 lb ai/A for lambda-cyhalothrin for army worm. 0.0326 to 0.052 lb ai/A for chlorantraniliprole and 0.0162 to 0.026 lb ai/A for lambda-cyhalothrin for cutworm. PHI 0 days for grazing or cut for forage; 7 days for cut grass to be dried and harvested for hay. Retreatment interval 7 days. REI 24 hr. Do not exceed 0.09 lb ai/A lambda-cyhalothrin or 0.2 lb ai/A chlorantraniliprole.
- cyfluthrin (Tombstone) at 0.025 to 0.03 lb ai/A. PHI 0 days. REI 12 hr. Retreatment interval 5 days. Do not exceed 0.176 lb ai/A per season.
- diflubenzuron (Dimilin 2L, Cavalier 2L, Unforgiven, Ventrilix 2L, Durant 2 L IGR) at 0.031 lb ai/A. PHI 1 day for cutting. REI 12 hr. Must be applied at first sign of hatch and before larvae reach 0.25 inch. Do not exceed 0.031 lb ai/A per cutting or 0.094 lb ai/A per year.
- gamma-cyhalothrin (Declare) at 0.0075 to 0.0125 lb ai/A. PHI 0 days for grazing or cut for forage; 7 days for cut grass to be dried and harvested. REI 24 hr. Do not exceed 0.045 lb ai/A per season.
- lambda-cyhalothrin (Warrior II, Lambda-Cy EC, Ravage II, Lamcap II, Crusader 2ME) at 0.015 to 0.03 lb ai/A. PHI 0 days for grazing and forage; 7 days to be dried for hay. REI 24 hr. Do not exceed 0.03 lb ai/A per cutting or 0.09 lb ai/A per season.
- malathion (Drexel Malathion 5EC, Malathion 57 EC, Fyfanon 57% EC, Martin's Malathion 57%, Gowan Malathion 8, Malathion 8-E)- Drexel Malathion 5EC, Malathion 57 EC, Fyfanon 57% EC, Martin's Malathion 57% at 1.25 lb ai/A; Gowan Malathion 8, Malathion 8-E at 1 to 1.25 lb ai/A. PHI 0 days. Limit 2 treatments per cutting. Retreatment interval 14 days. REI 12 hr. Armyworms only.
- methomyl (DuPont Lannate SP, Lannate LV, Annihilate LV, Lanveer SP) at 0.45 to 1.8 lb ai/A. PHI 7 days forage grazing; 3 days dehydrated hay. REI 48 hr. Do not exceed 1.8 lb ai/A per season. Group 1A, alternate with different IRAC groups to prevent insect resistance.
- methoxyfenozide (Engame, Troubadour 2F, Vexer DRV, WithStand, Insurgent, Intrepid 2F) at 0.06 to 0.16 lb ai/A. PHI 0 days for grazing, forage; 7 days hay. REI 4 hr. Do not apply more than 0.5 lb ai/A per year. Armyworms only.
- sodium borate (Prev-Am, Furor, Pronghorn) at 50 fl oz/100 gal. PHI 1 day. REI 24 hr. Retreatment interval 7 days.
- spinosad (Entrust SC, Kibosh SC, Estero SC, Blackhawk Naturalyte) at 0.031 to 0.0625 lb ai/A. PHI 3 days hay or fodder; 0 days pasture/forage. REI 4 hr. Armyworms only. Do not apply more than 3 times in any 21-day period or more than 6 times/season. Hazardous to honeybees for up to 3 hours post application. Limit 0.188 lb ai/A per season. OMRI-listed for organic use.
- zeta-cypermethrin (Mustang, Mustang Maxx, Cortes MAXX)-Mustang at 0.035 to 0.05 lb ai/A; Mustang Maxx or Cortes MAXX at 0.0175 to 0.025 lb ai/A. PHI 3 days for cutting or grazing; 7 days for seed. REI 12 hr. Do not apply more than 0.05 lb ai per cutting or 0.15 lb ai per season of Mustang or 0.025 lb ai per cutting and 0.075 lb ai per season of Mustang Maxx. Retreatment interval 7 days.
Management-Biological control
- Natural enemies such as Trichogramma spp. wasps parasitize armyworm eggs, reducing larvae before they emerge.
- Generalist predators such as (Pterostichus spp., Scarites spp., and wolf spiders) have been reported effective against armyworm.
- Mowing was reported to promote the activity of these generalist predators against armyworm.
Management-Cultural control
- Winter cover crops such as rye (Secale cereale L.) or vetch provide habitat for beneficial insects that prey on armyworms during the off-season.