Taking an environmentally sensitive approach to pest management


Integrated Pest & Crop Management



AUTHOR

Wayne C. Bailey
University of Missouri
Division of Plant Sciences
(573) 882-2838
baileyw@missouri.edu

High Numbers of Small Grasshoppers in Missouri

Wayne C. Bailey
University of Missouri
(573) 882-2838
baileyw@missouri.edu

Published: August 28, 2014

Numerous grasshoppers are currently present in grass pastures, waterways, field borders and many soybean and corn fields throughout most areas of the state. As grasses and other field border vegetation begin to mature and dry, grasshoppers will continue to move into crop fields to feed on green vegetation.Dry field conditions found in some areas of Missouri will favor grasshopper survival by reducing the threat from various viral pathogens that typically reduce grasshopper numbers in most years.The economic thresholds for grasshoppers vary depending on the commodity or non-cropland areas requiring insecticide applications for effective grasshopper management.

Approximately 100 plus species of grasshoppers are found in Missouri, although only 5-7 species are common in field crops. As with most insects, the larger the grasshoppers grow the more foliage and other plant materials they consume. Damage from both nymph and adult grasshoppers is often seen as very ragged feeding wounds located fromleaf edges inward into the body of the leaf. Grain damage is often found on the tips of corn ears, on sorghum (milo) heads, and the pods of soybean. As fall approaches, new plantings of alfalfa and wheat may be at risk from grasshoppers and cricket damage.

Economic threshold information and labeled insecticides are listed in the following commodity tables:

SITE: Grass Pastures
GRASSHOPPERS 2014

Comments: Control grasshoppers when they are small by applying spot treatments to hatching sitesor in grass pastures. Treatment in these areas is justified when grasshopper numbers reach or exceed 7 grasshoppers per square yard.
Common Name Trade Name Rate of formulated material per acre Placement Pre-harvest interval days
Beta-cyfluthrin *Baythroid XL 2.6 to 2.8 fl oz Broadcast 0 (grazing or forage)
zeta-cypermethrin *Mustang MAXX 3.2 to 4.0 fl oz Broadcast 0 (forage, hay),
17 (straw)
carbaryl Sevin XLR Plus 1 to 4 pt Broadcast 14 (harvest or grazing)
lambda-cyhalothrin *Warrior II 1.28 to 1.92 fl oz Broadcast 0 (grazing or forage)
7 (hay)
*Designates a restricted-use pesticide. Use is restricted to certified applicators only. Regardless of the formulation selected, read the label to determine appropriated insecticide rates,directions, precautions, and restrictions.

SITE: Alfalfa
GRASSHOPPERS 2014

Comments: Control grasshoppers when they are small by applying spot treatments to hatching sitesin non-cropland areas. Treatment in these areas is justified when grasshopper numbers reach or exceed 15 grasshoppers per square yard.
Common Name Trade Name Rate of formulated material per acre Placement Pre-harvestInterval (days)
beta-cyhalothrin *Baythroid XL 2.0 to 2.8 fl oz broadcast 0 (forage, hay)
chlorpyrifos + gamma-cyhalothrin *Cobalt 7 to 13 fl oz broadcast 7 (graze, hay)
dimethoate Dimethoate see product label broadcast 10 (harvest, graze)
chlorpyrifos *Lorsban Advanced 1/2 to 1 pt broadcast 7 (graze, hay)
gamma-cyhalothrin *Proaxis 2.56 to 3.84 fl oz broadcast 1 (forage) 7 (hay)
zeta-cypermethrin *Mustang MAXX 2.8 to 4.0 fl oz broadcast 0 (forage, hay)
carbaryl Sevin XLR Plus 1 to 3 pt broadcast 7 (harvest, grazing)
zeta-cypermethrin + chlorpyrifos *Stallion 9.25 to 11.75 fl oz broadcast 7 (cutting, graze)
cyfluthrin *Tombstone 2.8 to 4.0 fl oz broadcast 7( forage, graze, hay)
lambda-cyhalothrin *Warrior II 1.28 fl oz broadcast 1 (forage) 7 (hay)
*Designates a restricted-use pesticide. Use is restricted to certified applicators only. Regardless of the formulation selected, read the label to determine appropriated insecticide rates,directions, precautions, and restrictions.

SITE: Field Corn
2014 GRASSHOPPER spp.

Comments: Control grasshoppers when they are small by applying spot treatments to hatching sites in field borders and grass waterways. Treatment in CORN field is justified when 7 or more grasshoppers per square yard are present and foliage is being severely damaged. After pollen shed, control may be necessary if grasshoppers are damaging foliage above ear zone. Dimethoate should not be applied to corn during pollen-shed.
Common Name Trade Name Rate of formulated material per acre Placement REI Hours Pre-Harvest Interval Days
esfenvalerate *Asana XL 5.8 to 9.6 fl oz foliage 12 21 (grain)
cyfluthrin *Baythroid XL 1.6 to 2.8 fl oz foliage 12 21 (grain or fodder)0 (green forage)
bifenthrin *Brigade 2EC 2.1 to 6.4 fl oz foliage 12 30 (grain, fodder, graze)
chlorpyrifos + gamma-cyhalothrin *Cobalt 7 to 13 fl oz foliage 24 21 (grain or ears) 14 (graze or silage haravest)
deltamethrin *Delta Gold 1.5EC 1.0 to 1.5 fl oz foliage 12 21 (grain, fodder)12 (cut forage or graze)
alpha-cypermethrin Fastac EC 2.7 to 3.8 fl oz foliage 12 30 (grain, stover) 60 (graze)
dimethoate Dimethoate 4E 1 pt foliage 48 28 (grain) 14 (forage)
zeta-cypermethrin + bifenthrin *Hero 2.6 to 6.1 fl oz foliage 12 30 (grain, stover, graze) 60 (forage)
chlorpyrifos *Lorsban Advanced 1/2 to 1 pt foliage 24 21 (grain, ears ,forage, fodder)
chlorpyrifos *Lorsban 4E 1/2 to 1 pt foliage 24 21 (grain, ears, forage, fodder)
zeta-cypermethrin *Mustang MAXX 2.8 to 4.0 fl oz foliage 12 30 (grain, stover) 60 (forage)
chlorpyrifos *Nufos 4E 1/2 to 1 pt foliage 24 21 (grain or ears)
microencapsulated methyl parathion *Penncap-M 2 to 3 pt foliage 48 12 (grain, forage, graze)
gamma-cyhalothrin *Proaxis 2.56 to 3.84 fl oz foliage 24 Do not graze livestock
zeta-cypermethrin +chlorpyrifos *Stallion 9.25 to 11.75 fl oz foliage 24 30 (grain, stover, graze) 60 (forage)
cyfluthrin *Tombstone Helios 2.1 to 2.8 fl oz foliage 12 21 (grain or fodder), 0 (forage)
lambda-cyhalothrinn + chlorantraniliprole *Voliam xpress 6.0 to 9.0 fl oz foliage 24 1(forage) 7 (hay)
lambda-cyhalothrin *Warrior II 1.28 to 1.92 fl oz foliage 24 21 (grain), 1 (graze, forage) 21 (treated feed or fodder)

*Designates a restricted-use pesticide. Use restricted to certified applicators only.
Read the label and follow all insecticide rate information, directions, precautions, and restrictions.

SITE: Soybean
2014 GRASSHOPPER spp.

Comments: Treat when defoliation reaches 30% before bloom, 20% bloom to pod fill, or when 5% to 10% of pods are damaged.
Common Name Trade Name Rate of formulated material per acre Placement REI Hours Pre-Harvest Interval Days
esfenvalerate *Asana XL 5.8 to 9.6 fl oz Broadcast 12 21 (grain) Do not feed
beta-cyfluthrin *Baythroid XL 2.0 to 2.8 fl oz Broadcast 12 21 days, do not feed to livestock
chlorpyrifos + gamma-cyhalothrin *Cobalt 7 to13 fl oz Broadcast 24 30 (grain)Do not feed
deltamethrin * Delta Gold 1.5 to 1.9 fl oz Broadcast 12 21 (grain) do not graze, feed
dimethoate Dimethoate 4EC 1 pt Broadcast 48 5 (feed, graze)
chlorpyrifos Lorsban Advanced 1/2 to 1 pt Broadcast 24 30 (grain) do not graze, feed
lambda-cyhalothrin + thiamethoxam *Endigo ZC 3.5 to 4.5 fl oz Broadcast 24 30 (grain) do not graze, feed
Imadicloprid + cyfluthrin *Leverage 2.8 fl oz Broadcast 12 21(grain)
chlorpyrifos *Lorsban 4E 1/2 to 1 pt Broadcast 24 30 (grain) do not graze, feed
zeta-cypermethrin *Mustang MAXX 3.2 to 4.0 fl oz Broadcast 12 21 (grain)Do not feed
chlorpyrifos *Nufos 4E 1/2 to 1 pt Broadcast 24 30 (grain) do not graze, feed
acephate Orthene 97 1/4 to 1/2 lb Broadcast 24 21 days, do notfeed to livestock
lambda-cyhalothrin *Proaxis 3.2 to 3.84 fl oz Broadcast 24 30 (grain) Do not feed, graze
carbaryl Sevin XLR Plus 1 to 3 pt Broadcast 12 14 (graze, harvest) 21 (seed)
chlorpyrifos +zeta-cyhalothrin *Stallion 5.0 to 11.75 fl oz Broadcast 24 28 (grain)
cyfluthrin *Tombstone 2.0 to 2.8 fl oz broadcast 12 45 (feed) 60 (green forage)
lambda-cyhalothrin *Warrior II 1.6 to 1.92 fl oz Broadcast 24 30 (grain) do notfeed

*Designates a restricted-use pesticide. Use restricted to certified applicators only.
Read the label and follow all insecticide rate information, directions, precautions, and restrictions.

SITE: Grain Sorghum (Milo)
2014 GRASSHOPPER spp.

Comments: Control grasshoppers when they are small by applying spot treatments to hatching sites infield borders and grass waterways. Treatment in crop field is justified when 7 or more grasshoppers per squareyard are present.
Common Name Trade Name Rate of formulated material per acre Placement REI Hours Pre-Harvest Interval Days
cyfluthrin *Baythroid XL 2 to 2.8 fl oz grain head, foliage 12 14 (grain or graze)
chlorpyrifos + gamma-cyhalothrin *Cobalt 7 to 13 fl oz grain head, foliage 24 30 (grain, forage, fodder, hay, or silage)
gamma-cyfluthrin *Declare 1.02 to 1.54 fl oz grain head, foliage 24 30 (grain)
deltamethrin *Delta Gold 1.5EC 1 to 1.5 fl oz grain head, foliage 12 14 (grain, cut or graze forage)
dimethoate Dimethoate 4E 1/2 to 1 pt grain head, foliage 48 28 (grain) 14 (forage)
Alpha-cypermethrin *Fastac EC 3.2 to 3.9 fl oz grain head, foliage 12 14 (grain, stover) 45 (forage)
chlorpyrifos *Lorsban Advanced 1/2 to 1 pt grain head, foliage 24 30 (grain, forage, fodder, hay, or silage)
chlorpyrifos *Lorsban 4E 1/2 to 1 pt grain head, foliage 24 30 (grain, forage, fodder, hay, or silage)
zeta-cypermethrin *Mustang MAXX 3.2 to 4.0 fl oz grain head, foliage 12 30 (grain, stover) 45 (forage)
chlorpyrifos *Nufos 4E 1/2 to 1 pt grain head, foliage 24 30 (grain, forage, fodder, hay, or silage)
- *Stallion 9.25 to 11.75 fl oz grain head, foliage 24 30 (grain, stover) 45 (forage)
cyfluthrin *Tombstone Helios 2 to2.8 fl oz grain head, foliage 12 14 (harvest or graze forage)
lambda-cyhalothrin *Warrior II 1.28 to 1.92 fl oz grain head, foliage 24 30 (grain), 7 (graze) ,30 (straw fed to livestock)

*Designates a restricted-use pesticide. Use restricted to certified applicators only.
Read the label and follow all insecticide rate information, directions, precautions, and restrictions.

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