Agronomic Crops

PASTURE INSECT MANAGEMENT
Fall
Armyworms
Insecticide
b-cyfluthrin (P)
*Baythroid XL 1EC
Amount of
Formulation per Acre
1.6 – 1.9 oz.
Pounds Active
Ingredient per Acre
0.013 – 0.015
Acres 1 Gallon or
1 Pound Dry Will Treat
80 – 67
Pre-Grazing
Interval
0
Pre-Harvest
Interval
0
Application and Comments
0 day restriction for grazing or hay.
carbaryl (C)
Sevin XLR 4L
1.0 – 1.5 qt.
1 – 1.5
4 – 2.6
14
14
Must remove cattle. Do not apply within 14 days of harvest or
grazing. Other Sevin formulations are also available.
carbaryl (C)
Sevin 80WSP
1.25 – 1.88 lb.
1.0 – 1.5
0.8 – 0.53
14
14
Do not apply within 14 days of harvest or grazing.
chlorantraniliprole (D)
Prevathon 0.43SC
14 – 20 fl. oz
0.047 – 0.067
9 – 6.4
0
0
Remove livestock before spraying.
diflubenzuron (IGR)
Dimilin 2L
2 fl oz.
0.031
64
0
1
Allow 1 day after treatment before cutting for hay. Apply when
larvae are less than one-half inch in size.
λ-cyhalothrin (P)
*Karate Z 2.08CS
1.28 – 1.92 fl. oz.
0.02 – 0.03
100 – 66.7
0
7
Do not apply within 7 days of harvest; 0 day restriction for grazing.
Target larvae under one-half inch in size.
malathion (OP)
Malathion 57EC
1 qt.
1.25
4
0
0
Must remove cattle. Allow spray to dry before harvest or grazing.
methoxyfenozide (IGR)
Intrepid 2F
4 – 8 fl. oz.
0.06 – 0.12
32 – 16
0
7
Do not apply within 7 days of harvest; 0 day application restriction
for grazing.
spinosad (SPN)
Blackhawk 36% WDG
1.1 – 2.2 oz.
0.025 – 0.05
14.5 – 7.3
0
3
Do not apply within 3 days of harvest; 0 day restriction for grazing.
Do not allow grazing until spray is dry.
Z-cypermethrin (P)
*Mustang Max 0.8EC
2.8 – 4.0 fl. oz.
0.0175 – 0.025
45.7 – 32
0
0
0 day application restriction for forage or hay. Do not allow grazing
until spray is dry.
* Denotes restricted-use insecticides. Must have private or commercial applicators’ license to purchase and apply restricted-use insecticides.
Two types of armyworms commonly feed in hay and pastures in Mississippi. ey are tRUe ARMyWoRMs and FALL
ARMyWoRMs. True armyworms are a problem in early spring, and fall armyworms occur in late summer (beginning mid- to
late July).
e adults (moths) are rarely seen during the day but become active in the late evening and during the night. Female moths
lay eggs in the lower leaves of host plants. Feeding begins shortly after the eggs hatch. ese young larvae feed in the lower canopy,
close to the ground, until they are approximately 1 inch long. Once the worms reach this size, they can eat a large amount of
foliage.
Begin looking for true armyworm outbreaks in early spring and fall armyworm outbreaks mid- to late July. Scout fields on a
regular basis during periods of armyworm activity. Barnyard grass and broadleaf signal grass are favored hosts of armyworms. ese
are good indicator plants; if there are no worms on these hosts, your Bermuda grass is probably OK. Consider cost, efficacy, mode
of action, size of the larvae, grazing, and haying restrictions before choosing a product.
tHResHoLD: To prevent excessive damage, treat when you find three to five caterpillars per square foot. Do not count caterpillars
that are less than a quarter -inch long.
92 Pasture