Agronomic Crops

Corn
Earworms/
Armyworms
Insecticide
Foliar sprays
chlorantraniliprole (D)
Prevathon
flubendiamide (D)
Belt 4SC
Amount of
Formulation per Acre
14 – 20 oz.
2 – 3 oz.
Pounds Active
Ingredient per Acre
0.047 – 0.067
0.063 – 0.094
Acres 1 Gallon or
1 Pound Dry Will Treat
9 – 6
64 – 43
Application and Comments
λ-cyhalothrin (P),
chlorantraniliprole (D)
Besiege
5 – 10 oz.
25.6 – 12.8
methomyl (C)
Lannate 90SP
12 – 24 oz.
0.225 – 0.45
11 – 5
spinetoram (SPN)
Radiant SC
3 – 6 oz.
0.023 – 0.047
42.7 – 21.3
Except yellow-striped armyworms.
spinosad (SPN)
Blackhawk
(for corn earworm)
Blackhawk
(for fall armyworm)
2.2 – 3.3 oz.
1.67 – 3.3 oz.
0.05 – 0.074
0.038 – 0.074
7.3 – 4.8
9.6 – 4.8
Pyrethroids may not control bollworms. It is recommended to use only the highest labeled rate of pyrethroids.
CoRn eARWoRMs and FALL ARMyWoRMs are common pests that feed in the whorl before tassel. It is very important
to identify the species present in the field properly because some products recommended for corn earworms will not control fall
armyworms. Choose an insecticide effective against the complex of caterpillars when both species are present and control is necessary.
Corn earworm larvae vary greatly in color, from light green or pink to dark brown with alternating light and dark stripes running
lengthwise on the body. e surface of the larva is covered with small thorn-like projections (hairs). e fall armyworm has a
darker head capsule with a prominent white inverted Y. is is a distinguishing characteristic of the fall armyworm.
DAMAGe: Corn plants can tolerate considerable amounts of damage from whorl-feeding caterpillars. Populations seldom build
to damaging levels unless corn is planted after the recommended planting dates. Feeding by heavy, sustained infestations may lead
to deadheart and can reduce yield.
ContRoL: Timely planting is the preferred method of management. Plants in the seedling to early-whorl stage are the most susceptible
to damage. Check plants in this early-whorl stage regularly if planted after April 25. Whorl-feeding insects are in a protected
area, and the use of adequate spray volume is critical to get control. Apply insecticides in a minimum of 15 gallons of spray volume
per acre. Set nozzles to spray directly in the whorl. Aerial application will not give good control of worms feeding in the whorl. Several
of the new Bt corn technologies are effective at controlling corn earworms and fall armyworms in corn ears. However, reinfestation
levels can vary greatly, and the impact of corn earworm and fall armyworm ear feeding has not been fully investigated.
tHResHoLD: treatments are warranted when you detect an average of one or more larvae per plant from emergence to
mid-whorl stage. It is not considered economical to treat for corn earworms or fall armyworms in the ear.
56 Crop Corn Name