GRANULATE CUTWORM: Feltia subterranea, Noctuidae
ADULT: Wing span in these moths is smaller than for back cutworm and ranges from 1 1/4 to 1 3/4 in. Wing color varies greatly. Fore wings of male are beige to clay colored, shaded with black and darker at base and toward the front tips. Female fore wings are blackish with a pale area from base to orbicular spot near the leading edge, and an irregular pale band near the end of the wing. Both sexes are recognized by the black bar between the usually pale basal round (orbicular) and kidney-shaped (reniform) spots on the fore wings. Hind wings are off-white with veins and margins sometimes darker. Moths begin depositing eggs a few days after emergence.
EGG: The white (becoming darker with age), rounded eggs have flat bottoms and ribs radiating from the tops. Eggs are deposited singly or in small groups on the upper surfaces of leaves. Larvae emerge in 3 to 5 d.
LARVA: They are gray to reddish brown with dull yellowish subdorsal markings on the abdominal segments. The heads are yellowish to brownish. The undersurface of the body is flecked with white. Granules on cuticle are isolated, blunt, and pointing slightly backward. Sutures on front of head form an inverted "V". Larvae have three pairs of true legs and five pairs of prolegs. Larvae complete development in 22 to 32 d.
PUPA: Dark to reddish brown pupae are found in the soil. Adults emerge in 10 to 20 d.
GENERATION TIME: 50 to 70 d.
DAMAGE: Granulate cutworms attack most of the commercial vegetables grown in Florida. Larvae can cut off entire seedling plants, as well as climb and feed on leaves of older plants. This cutworm is not associated with weedy fields as is the black cutworm. First instar larvae stay on plants, while older larvae climb and feed on plants only during night.
CONTROL: This insect is attacked by wasp and fly parasitoids and a few diseases. These natural enemies, as well as predacious ground beetles, can exert tremendous control pressure that may approach 80%. However, seedlings emerging in fields without resident natural enemy populations can experience significant stand loss from first generation cutworms. Adults can be monitored with black light traps. Seedling corn should be scouted as frequently as twice per week to detect cutworms or their damage, particularly in areas known for this pest. Most larvae are found in and on soil beneath leaf trash during the day. Pesticides are available for at-plant, pre- and post-emergence broadcast and banded applications. Formulations, rates, and pre-harvest intervals of insecticides for granulate cutworm control are listed below for sweet corn (Table 1) and field corn (Table 2).
Table 1. Chemical control of granulate cutworms in sweet corn | |||
---|---|---|---|
Insecticide, formulation | Rate/acre | Min. days to harvest | Application notes |
carbaryl (Sevin, Sevin XLR Plus) 4 F, 4 EC | 2 qt | 2 ears; 48 fodder; 14** | banded |
carbaryl (Sevin) 80 WSP | 2.5 lb | 2 ears; 48 fodder; 14** | banded |
chlorpyrifos (Lorsban) 4 E *** | 2.4 fl oz / 1000 row-ft | 35 fodder, grain; 14 grazing, silage | banded at plant |
chlorpyrifos (Lorsban) 15 G *** | 8 - 16 oz / 1000 row-ft | 35 fodder, grain; 14 grazing, silage | banded or in-furrow at plant |
cyfluthrin (Baythrioid 2) 2 EC | 0.8 - 1.6 fl oz | 0 | |
cyhalothrin (Karate, Warrior) 1 EC | 2.56 - 3.84 fl oz | 1 | |
diazinon (D-z-n) 50 W | 4 - 8 lb | 7 | broadcast pre-plant |
diazinon (D-z-n AG500) 4 EC | 2 - 4 qt | 7 | broadcast pre-plant |
diazinon (D-z-n AG600) WBC | 51 - 102 fl oz | 7 | broadcast pre-plant |
esfenvalerate (Asana XL) 0.66 EC | 5.8 - 9.6 fl oz | 1 | |
ethoprop (Mocap) 10 G *** | 10.5 oz / 1000 row-ft | banded at plant, not in-furrow | |
ethoprop (Mocap) 6 EC *** | 1.4 - 2.9 fl oz / 1000 row-ft | banded at plant, not in-furrow | |
permethrin (Ambush) 2 EC | 6.4 - 16.0 fl oz | 1 | |
permethrin (Ambush) 25 WP | 6.4 - 16.0 oz | 1 | |
permethrin (Pounce) 1.5 G *** | 6.7 - 13.3 lb | 1 | broadcast or banded |
permethrin (Pounce) 25 WP | 6.4 - 12.8 oz | 1 | |
permethrin (Pounce) 3.2 EC | 4 - 8 fl oz | 1 | |
permethrin (Pounce WSB) 24.7% WSB | 6.4 - 12.8 oz | 1 | |
tefluthrin (Force) 3 G | 4 - 5 oz / 1000 row-ft | banded or in-furrow at plant | |
terbufos (Counter) 15 G | 8.0 oz / 1000 row-ft | banded or in-furrow at plant; suppression | |
terbufos (Counter CR) 20 G | 6.0 oz / 1000 row-ft | banded or in-furrow at plant; suppression | |
thiodicarb (Larvin) 3.2 EC | 20 - 30 fl oz | 0 ears; do not feed to livestock | |
**harvest or grazing of forage or silage | |||
***check label for other application techniques and rates |
Table 2. Chemical control of granulate cutworms in field corn | |||
---|---|---|---|
Insecticide, formulation | Rate/acre | Min. days to harvest | Application notes |
carbaryl (Sevin, Sevin XLR Plus) 4 F, 4 EC | 2 qt | 48 fodder, grain; 14** | |
carbaryl (Sevin) 80 WSP | 2.5 lb | 48 fodder, grain; 14** | |
chlorpyrifos (Lorsban) 4 E | 2 - 4 pt or 2.4 fl oz / 1000 row-ft | 35 fodder, grain; 14 grazing, silage | broadcast preplant or banded or in-furrow at plant |
chlorpyrifos (Lorsban) 15 G | 6.75 - 13 lb or 8 - 16 oz / 1000 row-ft | 35 fodder, grain; 14** | broadcast preplant or banded or in-furrow at plant |
cyhalothrin (Karate, Warrior) 1 EC | 1.92 - 3.20 fl oz | 21 | |
esfenvalerate (Asana XL) 0.66 EC | 5.8 - 9.6 fl oz | 21 | |
ethoprop (Mocap) 6 EC | 1.4 - 2.9 fl oz / 1000 row-ft | banded at plant, not in-furrow | |
ethoprop (Mocap) 10 G | 10.5 - 21.5 oz /1000 row-ft | banded at plant, not in-furrow | |
ethyl parathion (Parathion) 8 EC | 0.75 pt | 12 | climbing cutworms |
permethrin (Ambush) 2 EC | 6.4 - 12.8 fl oz | 30 harvest of fodder, grain | |
permethrin (Ambush) 25 W | 6.4 - 12.8 oz | 30 harvest of fodder, grain | |
permethrin (Pounce) 1.5 G | 6.7 - 13.3 lb / ac or 8 - 16 oz / 1000 row-ft | 30 harvest of fodder, grainv | broadcast or banded at planting or foliar |
permethrin (Pounce) 25 WP | 6.4 - 12.8 oz | 30 harvest of fodder, grain | broadcast or banded at planting or foliar |
permethrin (Pounce) 3.2 EC | 4 - 8 fl oz / ac or 0.3 - 0.6 fl oz / 1000 row-ft | 30 harvest of fodder, grain | broadcast or banded pre-emerge, at planting or foliar |
permethrin (Pounce WSB) 24.7% WSB | 6.4 - 12.8 oz | 30 harvest of fodder, grain | broadcast pre- or post-emerge |
tefluthrin (Force) 3 G | 4 - 5 oz / 1000 row-ft | banded or in-furrow at plant | |
terbufos (Counter) 15 G | 8.0 oz / 1000 row-ft | banded or in-furrow at plant; suppression | |
terbufos (Counter CR) 20 G | 6.0 oz / 1000 row-ft | banded or in-furrow at plant; suppression | |
**harvest or grazing of forage or silage |