Cutworms Reference Page
Top: Crops: Sugarbeets: Cutworms:
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Glassy cutworm Apamea devastator
Redbacked cutworm Euxoa ochrogaster ID photos:
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Spotted cutworm Xestia C-nigrum ID photos:
Variegated cutworm Peridroma saucia ID photos:
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Cutworm larvae are about 1 inch when mature and vary in color from light gray to dark brown, with faint stripes or fine mottles on their smooth, hairless, soft bodies. They curl into a motionless C-shape when disturbed.
Subterranean species feed on roots and stems, cutting off plants at the soil surface. Climbing species hide during the day in soil and either cut off plants at the soil surface or feed in the crown on newest leaves and stems.
Scouting and thresholds No formal economic thresholds exist for cutworm insecticide treatment decisions in sugar beets. Infestations typically are very spotty, usually occurring near weedy patches or along field borders. Consider spot treating infested sites rather than the entire field.
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a. (Azatin XL) at
0.01 to 0.02 lb ai/a. Foliar application primarily for climbing
cutworm
larvae.
b. (Aza-Direct) at 0.0123 to 0.0247 lb ai/a and up to 0.0432 lb ai/a under extremely heavy pest infestation.
3. carbaryl (Carbaryl 4L, Carbaryl Bait, Sevin 4F, Sevin XLR Plus, Sevin 80S, Sevin 80WSP, Sevin 5 Bait, Sevin RP4 and others at 1.5 lb ai/a. PHI 28 days. For Carbaryl 4L, Sevin 4F, Sevin XLR Plus, and Sevin 5 Bait, do not apply more than 3 lb ai/a per crop. For Sevin 80S and Sevin 80WSP, do not apply more than 4 lb ai/a per crop.
4. chlorpyrifos (Lorsban 4E, Nufos 4E, Yuma 4E, Govern 4E, Whirlwind, Warhawk, Pilot 4E and others
Preplant or at planting— Apply at 0.5 lb ai/a incorporated in 10-inch band over row. PHI 30 days. Do not allow livestock to graze in treated areas or harvest treated beet tops as feed for meat or dairy animals within 30 days after last treatment.
5. chlorpyrifos (Lorsban 15G, Lorsban 75 WG Nufos 15G, Chlorpyrifos 15G AG, Pilot 15G) preplant or at planting—Apply at 1.0 to 2 lb ai/a in 4- to 5- inch band at planting. Do not apply granules in direct contact with seeds. Do not make more than one application per year. Incorporate into the top ½ to 1 inch of soil.
6. chlorpyrifos (Chlorpyrifos 4E AG, Lorsban 4E, Lorsban 75WG, Nufos 4E, Yuma 4E, Govern 4E, Whirlwind, Warhawk, Pilot 4E)
Postemergence—Apply at 1 lb ai/a broadcast, or at 0.67 lb ai/a in a 5 to 7 inch band. PHI 30 days. Do not allow livestock to graze in treated areas or use harvest treated beet tops as feed for meat or dairy animals within 30 days after last treatment.
7. esfenvalerate (Asana XL) at 0.03 to 0.05 lb ai/a as seedling spray. PHI 21 days. Apply as necessary, but do not apply more than 0.15 lb ai/a per season. Apply with ground or air equipment using sufficient water (at least 2 gal/a) to provide uniform coverage.
8. methomyl—
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a. (Lannate LV)
at 0.75 to 3 lb ai/a. PHI 7 days, or 30 days if tops are fed to
livestock. REI
48 hr. Do not apply more than 15 lb ai/a per crop. Do not make more
than
10 applications per crop.
b. (Lannate SP) at 0.25 to 1 lb ai/a. PHI 7 days, or 30 days if tops are fed to livestock. REI 48 hr. Do not apply more than 4.5 lb ai/a per crop. Do not make more than 10 applications per crop.
10. terbufos (Counter CR Lock’n Load, Counter 15G Lock’n Load) at 1.2 oz ai/1,000 row feet—for suppression only . Apply at planting in a 5 to 7 inch band over the row and lightly incorporate. Do not allow granules to contact seed. Only one application per year. Do not exceed 2 lb ai/a.
11. zeta-cypermethrin—
a. Mustang. PHI 50 days. Do not apply more than 0.15 lb ai/a per season (at planting + foliar applications).
At planting application—Apply at 0.05 lb ai/a on soil surface in a 5 to 7-inch band, or broadcast in a minimum of 3 to 5 gal water per acre.
Foliar application—Apply at 0.028 to 0.05 lb ai/a with equipment for ground or air application, using sufficient water to obtain full coverage of foliage.
b. Mustang Max. PHI 50 days. Do not apply more than 0.075 lb ai/a per season of Mustang regardless of application method or formulation. ID and OR 24(c).
At planting application – Apply at 0.025 lb ai/a on soil surface in a 5 to 7 inch band, or broadcast in a minimum of 3 to 5 gal water per acre.
Foliar application – Apply at 0.014 to 0.025 lb ai/a by air or ground equipment using sufficient water to obtain full coverage of foliage. Use minimum of 3 gallons/a by air and 10 gallons/acre by ground.
SOURCE: 2007 PACIFIC NORTHWEST INSECT
MANAGEMENT
HANDBOOK
updated 5/6/08-jn
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