Agronomic Crops

Grasshoppers
Insecticide
Amount of
Formulation per Acre
Pounds Active
Ingredient per Acre
Acres 1 Gallon or
1 Pound Dry Will Treat
Threshold and Comments
gamma-cyhalothrin (P)
Prolex 1.25CS
Proaxis 0.5CS
1.28 – 2.05 fl. oz.
3.2 – 5.12 fl. oz.
0.0125 – 0.02
0.0125 – 0.02
62 – 100
25 – 40
λ-cyhalothrin (P)
Karate Z 2.08CS
Lambda 2.08CS
1.6 – 2.56 fl. oz.
1.6 – 2.56 fl. oz.
0.025 – 0.04
0.025 – 0.04
50 – 80
50 – 80
Z-cypemethrin (P)
Mustang Max 0.8EC
3.2 – 4.0 fl. oz.
0.02 – 0.025
32 – 48.5
Several species of grasshoppers may be found in rice fields. Green grasshoppers from the longhorn species usually feed on the
flower parts of the plants. e brown species feed on leaves and the sides of stems of rice plants. Injured plants will sometimes produce
white heads.
Grasshoppers are very seldom an economic problem in rice fields. However, during drought conditions, large numbers may
move into fields as food plants around the fields dry up. In most situations, only border treatment is necessary to control a damaging
population. Start checking the rice fields when rice is about 10 percent headed. Sample four to six locations. Sample fields at
least once a week with a sweep net until rice heads are mature.
tHResHoLD: treatments should be made when you find an average of 5 grasshoppers in 10 sweeps during the first 2
weeks of heading. After the field is completely headed and most of the heads are in the milk stage, treatments should be
made when you find an average of 10 grasshoppers in 10 sweeps.
Rice Water
Weevils
(Eggs)
Insecticide
clothianidin (N)
Belay
Amount of
Formulation per Acre
4.5 fl. oz.
Pounds Active
Ingredient per Acre
0.075
Acres 1 Gallon or
1 Pound Dry Will Treat
28
Threshold and Comments
Do not apply more than 0.075 lb. ai./acre per season.
(Adults)
diflubenzuron (IGR)
Dimilin 2L
12 – 16 fl. oz.
0.19 – 0.25
8 – 10.6
Apply an insecticide when adults and feeding scars are observed and conditions are
favorable for egg laying. Kills the eggs of rice water weevils. Apply 2 to 5 days after
the permanent flood has been established.
λ-cyhalothrin (P)
Karate Z 2.08CS
Lambda 2.08CS
1.6 – 2.56 fl. oz.
1.6 – 2.56 fl. oz.
0.025 – 0.04
0.025 – 0.04
50 – 80
50 – 80
Apply an insecticide when adults and feeding scars are observed and conditions are
favorable for egg laying. Kills only adult rice water weevils. Apply within a week of
permanent flood establishment.
Z-cypemethrin (P)
Mustang Max 0.8EC
3.2 – 4.0 fl. oz.
0.02 – 0.025
32 – 40
Rice Water
Weevils
(Larvae)
Rough Rice Seeding Rate
(lb./A)
100 – 120
90 – 100
80 – 90
60 – 80
30 – 40
≤ 30
thiamethoxam
Cruiser 5 FS
3.3
3.3
3.3
3.3
3.3
3.3
Rate in fl. oz. per 100 lbs. seed
chlorantraniliprole
Dermacor X-100
1.50
1.75
2.00
2.50
5.00
6.00
clothianidin
Nipsit INSIDE
1.92
1.92
1.92
1.92
1.92
1.92
e labeled rate for Cruiser is 0.03 mg of thiamethoxam per seed. erefore, the actual rate per 100 pounds seed may vary slightly based on the number of seeds per pound.
Rice water weevils occur throughout Mississippi’s rice-growing area. Fields planted to rice for several years usually have larger populations
than fields recently brought into production. e adults are grayish-brown, broad-nosed, and about one-eighth inch long.
Adults overwinter in grasses and ground trash near rice fields. ey are strong fliers and migrate into rice fields in the spring. Adult
weevils may be found in rice before flooding but usually invade fields in large numbers soon after flooding. If the field is flushed, water
weevils may be attracted before a permanent flood is established. Weevil activity is more common in areas with open water, such as
around levees, and thin stands. Higher populations are usually found in fields flooded between late May and mid-June.
82 Rice