grasshoppers - all star training · pdf filegrasshoppers grasshoppers have been an economic...

Grasshoppers

Grasshoppers have been an economic concern in the western United States since settlers established farming

and ranching operations there in the 1800s. Settlers suffered a severe hardship in 1864 because grasshoppers

ruined crops. In 1873 many of its homesteaders left, discouraged by economic conditions and grasshopper

hordes. The settlers of the frontier faced many challenges including the threat of horrendous weather,

starvation, plagues, and sickness. For example, in 1874 there was a giant Grasshopper Plague that swept in a Z-

shape across the lands of Oregon, Dakota Territory, Kansas, and Missouri. Lakes of grasshoppers three inches

deep were not uncommon. They devoured the crops, the vegetables, clothing, the wool on live sheep, and even

each other, causing many of the settlers to leave the lands. During the 1870s the Rocky Mountain locust,

Melanopus spretus (Walsh), destroyed crops throughout the West, and in 1877 the U.S. Entomological

Commission was created to investigate the problem.

Although Rocky Mountain locust problems subsided in the

1880s, interest and concern regarding grasshopper damage

have not subsided.

The expansion of urban areas into foothills, prairies, and

farmland has increased concern over grasshoppers.

Grasshopper numbers build to high levels in weedy areas and

migrate to yards where they destroy vegetable and flower

gardens and ornamental shrubs. While extreme economic loss

may not be associated with this situation, the aesthetic value

of homes and the happiness of homeowners are threatened.

Current emphasis of large-scale grasshopper management efforts has shifted from crop protection to rangeland

protection. This shift has occurred because farmers can use numerous insecticides to effectively suppress

grasshoppers, and, perhaps more important, they have the economic incentive to affect control. Other factors

also work to reduce impact of grasshoppers on cropland. Insecticide applications directed toward the myriad of

other insect pests associated with crops help keep grasshopper numbers low. Such practices associated with

crop production as tillage, ditch burning and weed control also reduce grasshopper abundance. Ranchers, on the

http://www.gov.mb.ca/agriculture/crops/i

nsects/forecast/grasshopper interp.html

© 2014 All Star Training, Inc. 1

other hand, also have effective insecticides at their disposal, but low productivity of rangeland relative to

cropland precludes their investment in expensive control procedures.

In addition to yield reduction in forage, the cost of grasshopper

control is an important direct cost ranchers must incur; indirect

costs include reduction in weight gain by cattle and relocation

costs. Grasshoppers consume from 6% to 12% of the available

forage in the western United States although in some localities they

consume essentially all available forage. Grasshoppers eat

approximately one-half of their body weight in green forage per

day. With a grasshopper population of seven or eight per square

meter in a four hectare field, grasshoppers consume as much forage

as a cow. The U.S. Department of Agriculture suggests that

treatment is justified when grasshopper numbers (adults or late instar nymphs) reach approximately nine per

square meter.

Few grasshopper control recommendations consider forage condition, grasshopper species and other important

variables. When forage density or biomass is low, small numbers of grasshoppers per unit area can be

damaging. Thus, during dry periods, when grasshopper numbers often are highest, fewer grasshoppers can be

tolerated. When the price of cattle is high, ranchers can better afford grasshopper suppression costs, and control

operations are more likely instigated.

Grasshoppers differ significantly in their damage potential. Forage loss stems from both consumption and

clipping without consumption (wastage). Studies such as these suggest that over a season, mixed populations of

grasshoppers destroy approximately 44 mg (dry weight) of foliage per grasshopper per day. Wastage by

clipping may represent up to 50% of total forage reduction attributable to grasshoppers. Both consumption and

wastage rates are influenced by grasshopper preference for a plant species; favored plants are more heavily

damaged.

Biology and Life Cycle

Grasshoppers belong to the class of insects.

Their general anatomy consists of a head, thorax

(mid-section), and abdomen. They have 3 pairs

http://sflwww.er.usgs.gov/.../critters/grasshopp

er.html


http://sflwww.er.usgs.gov/virtual_tour/kids/critters/grasshopper.html



of legs all attached to the thorax. They have a tracheal system for breathing and two pairs of wings. They are

further classified into the order of orthoptera. Grasshoppers may next be placed in the family Acrididae because

they possess short antennae and ovipositor (egg-layer), an auditory organ (tympanum visible externally) on each

side of the first abdominal segment, and three-segmented tarsi (feet). See Table 1 summarizing the affiliation of

the Carolina grasshopper, Dissosteira carolina (Linnaeus).

TABLE 1. Affiliation of the Carolina grasshopper, Dissosteira carolina (Linnaeus),

with the categories of taxonomic hierarchy and the associated characteristics.

CATEGORY TAXON CHARACTERISTICS

Kingdom Animalia Sensitivity, voluntary movement, require oxygen and

organic food, fixed organs.

Phylum Anthropoda Ringlike segments, jointed appendages, exoskeleton.

Class Insecta Three body regions, three pairs legs, one pair antennae,

tracheal system, usually two pair wings.

Order Orthoptera Forewings leathery, hindwings membranous, chewing

mouthparts, hindlegs enlarged for jumping, simple

metamorphosis.

Family Acrididae Short antennae, short ovipositor, tympanum on first

abdominal tergum, three segmented tarsi.

Genus Dissosteira High median pronotal crest deeply cut by one sulcus,

body slender, medium to large size.

Species carolina Hindwings black with yellow margin; tegmina unicolorous

or faintly spotted.

The Head


The head of a grasshopper contains large, strong muscles which operate the chewing mouthparts. Also

contained in the head is the brain and subesophageal ganglion. These two organs serve as the body’s main

centers of the nervous system. The prominent features on the outside

of the head are a pair of antennae, two compound eyes, and the

mouthparts. The antennae will have one of three different shapes,

filiform or threadlike, ensiform or sword-shaped, and clavate or club

shaped.

Thorax

The thorax, locomotion center of the grasshopper, is a stout, boxlike structure consisting of three fused

segments: the prothorax, mesothorax, and metathorax. Each segment bears a pair of legs. The second segment

bears a pair of forewings, the tegmina, and the third segment a pair of membranous hindwings. The wings of a

few species are reduced to small pads or are entirely lacking. The top of the thoracic segments is called the

notum, the bottom the sternum, and the sides the pleura.

Legs

Although the three pairs of legs have the

same component parts, the hind pair,

adapted for jumping, are much larger than

the first and second pair and bear more

distinctive features. The color and

markings of both the femur and tibia differ

among species. The robust femur has

several surfaces and ridges that have been

given names for easy reference.

The long and slender tibia bears along its posterior edges a double row of spines and distally two pairs of

articulated spurs or calcars. The number of spines and the length of calcars vary among species. The inner

medial area of the femur may have a longitudinal ridge bearing a series of stridulatory pegs. Up and down

movements of the hindlegs cause the pegs to scrape against a raised vein on each tegmen, which produces a

song or signal peculiar to that species of grasshopper.

Wings © 2014 All Star Training, Inc. 4

The two pairs of grasshopper wings differ in shape,

structure, and function. The front pair, or tegmina, are

leathery and narrow with the sides nearly parallel. The

hind wings are membranous and fan-shaped. Compared

with the tegmina, the hind pair contributes three times as

much to flight lift. Both pairs afford diagnostic characters

that aid in the identification of species. The wing veins,

sclerotized tubes providing strength to the wings, vary

greatly in thickness. The tegmina vary from immaculate

to distinctly spotted or marked. The hindwings of

grasshoppers are usually hyaline. Members of one

subfamily, the Oedipodinae or bandwinged grasshoppers,

have wings with a dark submarginal band and have the

disk colored.

Abdomen

The hind region of the grasshopper’s body, the abdomen,

consists of 11 segments. Segment I is firmly fused with the

metathorax and contains the auditory organ with its

eardrum cover, the tympanum.

Segments II to VIII are ringlike in appearance and are

separated from one another by pliable membranes. Each

segment has a sclerotized tergum that covers not only the

top but also the sides of the abdomen. A sclerotized

sternum covers the bottom. Pliable membranes separate the

terga from the sterna and with the intersegmental

membranes allow the abdomen much flexibility, a requirement for respiratory movements, copulation, and

oviposition.

Grasshopper Populations


Grasshopper infestations or assemblages consist of the individuals of several species that live together in the

same habitat sharing or competing for available food and space. Members of the dominant species outnumber

members of other species and may make up more than 50 percent of the assemblage. Occasionally two or three

species may become codominants. No evidence has been found for any essential

relationship among species that brings them together. The habitat affords the

minimum requirements for all the permanent species and ample measure for the

abundant.

Grass-feeding species of grasshoppers are the most numerous in grasslands. In a

northern mixedgrass prairie site 18 miles northwest of Fort Collins, Colorado, a

total of 24 species were recorded during an outbreak in 1981. Of the total, 14 were

grass feeders, six were mixed feeders, and four were forb feeders. The number of

individuals of grass-feeding species made up 85% of the total population. The

dominant grasshopper, Ageneotettix deorum (Scudder), contributed 52% of the

population. A second example of an outbreak population in northern mixedgrass prairie was the assemblage

inhabiting a site 15 miles north of Hartville, Wyoming, where 16 species were recorded. Nine species were

grass feeders, one a mixed feeder, and six were forb feeders. The number of individuals of grass feeding species

made up 89% of the population. The dominant grasshopper, Aulocara elliotti (Thomas), contributed 74% of the

population.

The composition of grasshopper assemblages is characteristic of various grassland types. A scout working in a

western state expects particular species to compose economic infestations in certain areas. Because the species

composition of grasshopper assemblages infesting particular habitats remains almost the same year after year, a

scout is aided in identifying nymphs by knowing the species that were present as adults during past years.

Widespread species with high biotic potential, such as Aulocara elliotti and Ageneotettix deorum, inhabit many

grassland types and become abundant members in various assemblages of grasshoppers. In outbreaks on desert

grasslands of Arizona and New Mexico, for example, A. elliotti is often the dominant species, as in many

infestations of the northern mixedgrass prairie.

www.sidney.ars.usda.gov/.../Hand

book/IV/iv_4.htm


http://www.sidney.ars.usda.gov/grasshopper/Handbook/IV/iv_4.htm

http://www.sidney.ars.usda.gov/grasshopper/Handbook/IV/iv_4.htm

Grasshoppers defoliate grasses by direct feeding

on leaf and stem tissue and by cutting off leaves

or stems and heads while feeding. High

populations of grasshoppers on rangeland can

damage plant crowns so severely that many grass

plants will not recover. With the exception of the

migratory grasshopper, rangeland grasshopper

species rarely feed on crops, except during years

of very high populations. Understanding how

grasses respond to defoliation is critical for

grasshopper management on rangelands. Each

year, rangeland vegetation is defoliated by

livestock, wildlife, insects, hail and/or fire. Grasshoppers can rapidly remove a large percentage of the foliage.

Root growth stops and nutrient uptake is reduced for several days when more than half of the green herbage is

removed from grasses. Lengths of "shut-down" and "slow-down" periods in roots increase as severity and

frequency of defoliation increase. Removing more than 65 percent of the green herbage one time during the

growing season can reduce total root length by 30 percent or more. When grasses are severely defoliated over

several years by any combination of processes, plants become weak and die. Grasses in excessively defoliated

pastures are drought stressed even when precipitation is near average because reduced root length limits access

to available soil moisture. Plants on shortgrass prairie are least likely to experience defoliation-induced drought

because low infiltration rates limit the depth of soil moisture on these sites.

Biological Control

Rangeland, pasture, and forage insect pests consume 10 to 25% of forage production and cause substantial

economic losses. The rangeland livestock industry is beset by problems associated with natural variation in

annual forage production, which is exacerbated by extreme variations in grasshopper infestations. Rangeland

and pasture managers must choose among several unattractive management alternatives, including forced sale

of livestock; reducing the stocking rate; buying hay; renting

more pasture; spraying; or no action, which can lead to

serious overgrazing. In order to effectively control

http://www.ars.usda.gov/main/site_main.htm?modecode=53-41-00-00


grasshopper populations biologically it is important to understand two things:

1. Make the environment as unfavorable as possible for grasshopper growth and survival of pest species of

grasshoppers.

2. Maintain high levels of plant vigor and range conditions to minimize the effects and occurrence of

outbreaks.

Unfavorable Environment

Grasshoppers are small, cold-blooded, and profoundly affected by

temperature and relative humidity in their microhabitat. All developmental

stages of grasshoppers can be advanced by high temperatures or retarded by

low temperatures. Increasing the time required for grasshoppers to mature

increases juvenile mortality, which reduces defoliation and the number of

eggs produced for next year’s grasshopper population. Temperatures and

relative humidity near the soil surface are directly related to the height and

distribution of herbage. Increases in herbage that delay grasshopper growth

also provide habitat for natural predators and pathogens, including birds, mammals, reptiles, predatory insect

species, fungi and other pathogens. Management practices that minimize favorable habitat for pest species of

grasshoppers also maintain high levels of plant vigor and range condition. The number of grasshopper species

and the total number of grasshoppers may be greater on properly managed prairie compared to overgrazed

prairie; however, reduced grasshopper growth rates, higher mortality of immature grasshoppers, and higher

productivity of plants minimize the effects of these populations.

How weather affects grasshoppers.

http://www.agr.gov.sk.ca/docs/production/grasshopperff.asp

http://www.agr.gov.sk.ca/docs/produ

ction/grasshopperff.asp


Temperature Effects

• High temperatures in summer – fall

◊ Early maturity of grasshoppers

◊ Long egg laying period

• Warm spring

◊ Early hatch, followed by:

<70o -->No feeding, high

mortality

◊ Warm and dry --> Good start for

hoppers

• Winter temperatures have little affect

Rainfall Effects

• Cloudy, wet weather for 1+ weeks

◊ Promotes fungal pathogens of

grasshoppers

◊ Prolonged wet period important

• Heavy rains during emergence

◊ Kills young grasshoppers

◊ embeds young hoppers in soil

◊ physically wash them away

• Extreme drought

◊ Poor egg hatch

◊ Hoppers starve from lack of food

◊ Low egg production by adults

Weather effects and their impact on grasshopper populations.

Decrease when . . . • Warm early spring

◊ premature hatch

◊ IF get a cold snap --> poor

development

• Hot period in early spring...

◊ promotes hatching

◊ hatching followed by cloudy, wet

weather favors the occurrence of

disease

• Cool summer and early fall

◊ delays the maturity of the

grasshoppers

◊ shortens the time for egg laying

Increase when . . . • Cool, wet weather in early spring

◊ prevents premature hatch

◊ insures adequate food supply

• Warm and dry in late spring

◊ promotes uniform hatching time

◊ good weather conditions for

feeding

• Hot summer with adequate rainfall

◊ provides good food supply

◊ low incidence of disease

• Late fall

◊ long egg laying period


Herbage Allocation

Soil can be shaded or insulated from direct sunlight with standing herbage or litter. On healthy rangeland,

standing herbage consists of a mixture of residual herbage from preceding years and current-year herbage. A

minimum amount of standing herbage must be retained at all times for protection against erosion and to

enhance infiltration of precipitation. About half of the herbage produced each year is needed to maintain levels

of residual cover typical of healthy rangeland. Disappearance of the other half by the end of the summer grazing

season is the result of nearly equal defoliation by cattle and natural processes. On properly stocked rangeland,

cattle will use about 25 percent of the current-year herbage resource.

Published estimates of herbage reduction caused by grasshoppers are highly variable. While these insects are a

natural part of range ecosystems, herbage losses caused by above average populations must be offset by reduced

livestock use. Estimates of daily dry matter intake for grasshoppers range from 30 to 250 percent of body

weight compared to 1.5 to 2.5 percent for beef cattle. A 1250-pound cow would consume 19 to 31 pounds of

herbage each day. The same amount of herbage could be consumed by eight to 104 pounds of grasshoppers in a

single day. Many ranchers develop a mental picture of what pastures should look like when it is time to remove

livestock. Cattle should not be placed in grasshopper-infested pastures that appear to be near or below that

amount of cover envisioned as adequate by the rancher.

Plant Communities

Opportunities to shade the soil surface with standing herbage increase as composition of mid- and tallgrass

species increases. Full growing-season deferment from green-up to killing frost can dramatically increase mid-

and tallgrass herbage production after one to five drought-free years of overgrazing. The probability of

increasing shade by improving range condition or plant vigor declines as the history of abuse increases.

Decades of overgrazing can reduce mid- and tallgrass prairies to shortgrass dominated pastures that do not

respond well to best management practices. Deterioration of rangeland is accelerated when drought and heavy

defoliation are combined.

Best Grazing Management Practices

Cattle should be excluded for one year from pastures that are severely

defoliated to replenish residual herbage and to provide uninterrupted

plant growth for maximum replenishment of roots and energy


reserves. It may be necessary to rest a pasture for an additional year if precipitation is below average or if the

vegetation is heavily defoliated by other processes during deferment.

Recovery of plant vigor is maximized with full growing-season deferment and is not affected by dormant-

season grazing at proper stocking rates. Grazing practices that alternate the season of grazing or shift summer

grazing dates by 30 days or more among pastures prevents repetitively favoring the same pest species of

grasshopper in consecutive years. Periodically changing grazing between growing and dormant seasons will

change grasshopper environments dramatically and maximize plant vigor. Pastures should be grazed once from

June to August to avoid severe defoliation of warm-season grasses. Grazing is generally distributed more

uniformly throughout pastures with rotation compared to continuous grazing. Consequently, rotation grazing at

proper stocking rates will minimize the development of large open areas near water that are common to

continuously grazed summer pastures.

Grasshopper disease and Predators

Disease-causing microorganisms have been investigated as potential biological control agents of grasshoppers

for many years. Probably the most well-know case has been the parasite Nosema locustae, a pathogen that was

selected in the early 1960’s for development as a microbial control agent for use in long-term suppression of

grasshoppers. Nosema locustae is the only registered microbial agent that is commercially available for control

of rangeland grasshoppers. Nosema has been studied more than any other microbial control agent for the

suppression of grasshopper populations. Application of Nosema formulated on a wheat bran bait have resulted

in numerous successful introductions of the pathogen into field populations.

Fungi can devastate whole populations of

grasshoppers. Some these fungi cannot grow without

a grasshopper host; other fungi are easily cultured in

the laboratory and can infect a wide range of insects

including grasshoppers. There are two main groups

of fungi that have species pathogenic to

grasshoppers: the zygomycetes and the

deuteromycetes. The zygomycetes pathogen infects

three different types of grasshoppers. Disease

symptoms in the advanced stage are characteristic

http://www.nps.gov/plants/alien/fact/lecu1.htm


and easy to recognize. Shortly before death, infected grasshoppers crawl to the tops of plants, fence posts, or

any other elevated position. There they die with their legs wrapped around the plant stalk and heads pointed

upward. Disease characteristics of deuteromcycetes infection include an external white or green mycelial

(filament like fungus) growth.

Insect Predators and Parasites of Grasshopper Eggs.

Grasshopper eggs are normally deposited in clusters, called

egg-pods; placed just below the surface of the soil. The egg-

pod is covered by a fairly durable coating of soil particles

mixed with a glutinous substance excreted by the female as

she lays her eggs in the soil. The female thrusts her abdomen

into the soil to a depth of an inch or two and starts laying her

eggs. When the cavity formed by her abdomen in filled with

eggs, she commonly blocks the hole above the eggs with a

glandular secretion forming a “froth plug.”

The egg-pod may contain from 2 to more than 100 eggs, depending on the species of grasshopper. The eggs

are quite tough and very resistant to cold. They are able to survive the most severe winters if the ground is not

disturbed. Also, there is usually enough moisture in the surrounding soil to keep the eggs from drying out even

in drought conditions. After the eggs have been deposited in a suitable spot, the female grasshopper provides

no maternal or defensive care and merely abandons them.

One form of biological control is to encourage grasshopper egg predators.

These predators attack the egg-pod as a whole and feed on the eggs,

thereby reducing grasshopper populations. Some grasshopper egg-pod

predators include the larvae of blister beetles, the larvae of certain

bombyliid flies, larvae of carabid beetles.

There is also a group of egg parasites that feed internally within a single

egg.

Chemical Control

http://www.sidney.ars.usda.gov/grasshopp

er/ID_Tools/F_Sheets/4spotted.htm


http://www.osha.gov/SLTC/youth/agriculture/chemicals.html

If control is needed, these

practices are most effective

when applied to grasshopper hatching areas

while hoppers are in early nymphal stages. If

populations are reduced to less than one

grasshopper per square yard, control

measures may not be needed for several

years unless the area is reinfested through

migration from other infested areas.

Grasshoppers may be controlled by directly applying insecticides. The insecticides currently registered for use

on rangeland are dimilin, malathion, and carbaryl (Sevin). Rates for these products are listed on the labels. If

larger grasshoppers are targeted, the higher labeled rates should be used. Other insecticides are labeled for

control of grasshoppers in forages, grasses, alfalfa, and other crops.

Applying insecticides as sprays or baits may control grasshoppers. The insecticides registered for use on

rangeland are malathion, acephate (Orthene), methyl parathion (Penncap M) and carbaryl (Sevin). Rates for

these products are listed on the labels. If larger grasshoppers are targeted, the higher labeled rates should be

used. Other insecticides are labeled for control of grasshoppers in forages grasses, alfalfa, and other crops. Read

labels thoroughly before using any insecticide, and observe safety and grazing restrictions.

Recent research at the University of Wyoming has demonstrated the effectiveness of a new grasshopper control

strategy in rangeland. This strategy has been termed Reduced Agent/Area Treatment (RAATs). The insecticide

that shows the most effectiveness with this method is Sevin XLR (ultra-low volume, aerial applications) which

is used at half the recommended rate (eight ounces per acre) instead of the full rate (16 ounces per acre). Also,

with this method only 50 percent of the area is treated by leaving every other spray strip untreated. This method

cuts control costs by 60 percent, and will significantly lower the economic threshold for grasshoppers in

rangeland. Grasshopper control in the RAATs area lagged a little behind control in the full rate areas, but by six

days after treatment both treatments showed the same level of control. The reasons for this dramatic control are

thought to be due to grasshopper movement into the treated strips while the insecticide is still effective, and to

the preservation of natural enemies in the untreated strips.

http://en.wikipedia.org/wiki/Crop_duster


Ranchers may

also need to

consider

protection-

spraying

"barriers"

around

valuable forage production areas, such as highly productive hay

meadows or seeded crops like alfalfa or annual forages. Protection

spraying may require continual surveys during the summer. As the

vegetation on upland range sites matures or dries, grasshoppers will

move into areas with succulent vegetation. Thus, it may be necessary to spray at two- or three-week intervals to

provide protection for these valuable forage resources.

Baits, once the most popular control method, have been replaced by sprays. However, baits are still used

occasionally in some circumstances on rangeland with short, dry vegetation. Carbaryl (Sevin) 5% bait is

available. Control of some grasshopper species will be severely limited because they will not feed on the bait.

For successful control, this method requires uniform distribution of bait and re-application if the bait no longer

is attractive to the grasshoppers. Attractiveness of the bait will be reduced substantially by rain or heavy dew.

Insecticides Labeled for Grasshopper Control in Pastures or Rangeland

• Malathion 57 EC: Use 1 ½ to 2 pts per acre. There are no grazing or harvest restrictions.

• Malathion ULV: Use 8-12 fluid ounces per acre. This product is specifically designed for aircraft and

ground equipment capable of applying ultra low volumes. There are no grazing or harvest restrictions.

• Carbaryl: Sevin 4F and Sevin XLR. Use ½ to 1 qt per acre.

Restrictions:

Rangeland: May be harvested or grazed the same day as application. Do not make more than one application

per year.


Pasture: Do not apply within 14 days of harvest or grazing. Do not

exceed 3 3/4 pounds per acre per year. Up to two applications per year

may be made but not more often than once every 14 days.

• Carbaryl: Sevin 4-Oil ULV. Use 3/8 to 1 qt per acre.

For use only on rangeland. This product is not labeled for pastures.

Restrictions: Do not make more than one application per year. May be harvested or grazed the same day as

treatment. Do not apply more than one quart per acre per year.

• Carbaryl: Sevin 80 WSP. Use 2/3 to 11/4 lb per acre.

Restrictions:

Rangeland: May be harvested or grazed the same day as application. Do not make more than one application

per year.

Pasture: Do not apply within 14 days of harvest or grazing. Do not exceed 3 3/4 pounds per acre per year. Up

to two applications per year may be made but not more often than once every 14 days.

• Methyl Parathion 4 lb/gal. Use 1½ pints per acre.

Restrictions: This is a restricted use product and is very toxic. Do not apply within 15 days of harvest or

grazing. Helena Chemical Co. formulates their product under the trade name of 4 lb. Methyl Parathion. Griffin

Chemical Co. formulates methyl parathion under the trade name of Declare.

• Diflubenzuron: Dimilin 25W. Use 0.5 to 1.0 oz per acre.

Note: this is a restricted use pesticide and is labeled for rangeland only. Do not exceed a total of 1.0 oz per

acre per year. There are no harvest or grazing

restrictions.

• Diflubenzuron: Dimilin 2L. Use 0.5 to 1.0 fl

oz per acre.

http://en.wikipedia.org/wiki/Grasshopper


Note, this is a restricted use pesticide and is labeled for rangeland only. Do not exceed a total of 1.0 fl oz per

acre per year. There are no harvest or grazing restrictions.

Non-Crop Areas

(field borders, fencerows, roadsides, ditch banks borrow pits)

The products listed for pasture and rangeland in addition to

acephate can be used for grasshopper control in these non-

crop areas.

• Acephate: Orthene 75SP and Orthene 97

Note: These products are labeled for Non-Crop areas (field borders, fencerows, roadsides, ditch banks

borrow pits). They are not labeled for pasture or rangeland grasses.

• Acephate: Orthene 75 SP use 1/3 lb per acre. Do not graze or feed vegetation cut from treated areas.

• Orthene 97 use 1/4 lb per acre. Do not graze or feed vegetation cut from treated areas.

• Grasshopper baits

Cereal grain baits formulated with carbaryl, Sevin XLR,

can be used for grasshopper control.

• SEVIN XLR

DIRECTIONS FOR USE AS A CEREAL GRAIN

BAIT: FOR END USE ONLY. NOT FOR

REPACKAGING. FOR USE ONLY BY GOVERNMENT

PERSONNEL OR PERSONS UNDER THEIR DIRECT

SUPERVISION (e.g., USDA, STATE AND LOCAL

EXTENSION PERSONNEL, ETC.)

Mixing InstructionsMix the appropriate amount of SEVIN® brand XLR Plus Carbaryl Insecticide with a cereal

grain substitute (cereal grains or their by-products, such as flaky wheat bran, rolled wheat, rolled oats and/or

barley or oat millings) to make a carbaryl bait containing 2% to 10% active carbaryl. For example, for a bait

http://www.oregon.gov/ODOT/TD/TDATA/gis/sr_sam.shtml

http://www.usda.gov/oc/photo/01di1349.htm


containing 5% carbaryl, mix 1 quart SEVIN® brand XLR Plus Carbaryl Insecticide (contains 1 lb. active

carbaryl) with each 19 pounds of cereal grain substrate. Mix only the amount of bait necessary for each insect

control program.

Storage Instructions

Store carbaryl bait in a cool, dry area out of reach of children and animals. Do not contaminate water, food, or

feed by storage or disposal. NOTE: Carbaryl bait should only be stored temporarily while awaiting application.

Application Instructions

Applications may be made with ground equipment (hand cyclone spreader) or with aerial application equipment

with a metered bait spreader attachment.

PASTURES, RANGELAND, WASTELAND, ROADSIDES

Use 0.50 lbs. active ingredient/acre for the control of grasshoppers and Mormon crickets. Use of oil bait assay is

suggested for control of high grasshopper populations. Do not make more than 1 application per acre per year.

May be harvested or grazed the same day as treatment.

SITE ECONOMIC THRESHOLD

Non-cropland areas, range

or grass pastures 8 or more nymphs present per square yard in grass pastures or 15 or more nymphs

present per square yard in non-cropland areas

Grasshopper control in pastures Grasshopper control in non-cropland areas

Insecticide Rate of formulated

material/Acre Insecticide

Rate of formulated

material/Acre

Malathion 57% 1.5-2 pt. *Asana XL 2.9-5.8 oz.

*Penncap M 2-3 pt. Imidan 70-W 2 1/8 to 2 3/4 lb.

Sevin XLR Plus 1-4 pt. *Penncap-M 2-3 pt.


Sevin 80S 2/3-1 7/8 lbs. Sevin XLR Plus 1-3 pt.

Sevin 4-Oil ULV 3/4-2 pt. Sevin 80S 2/3-1 7/8 lbs.

Sevin 4-Oil ULV 3/4-2 pt.

*Designates a restricted use pesticide. Be sure to follow all label directions, restrictions and precautions. Control of

grasshoppers is most easily achieved in non-cropland or grass pastures. If control is needed in crop fields, then use the

following table of thresholds, insecticides and rates as your guide in treating grasshopper problems.

The following tables list the economic threshold for grasshopper infestations in a variety of crop and non-

cropland areas. Also included is a listing of recommended insecticides and a range of use rates for formulated

material per acre. At this time in the season, use of rates in the upper end of the range are recommended when

attempting to control large nymphs and adult grasshoppers. If ground application equipment is used, apply a

minimum of 15 gallons of water/insecticide spray per acre for optimal coverage in thick crop canopies. Be sure

to read and follow all pesticide label directions and precautions.



Grain sorghum (milo) 7 or more nymphs or adults present per square yard

Grasshopper control in grain sorghum (milo)


material/Acre

*Baythroid 2 2.0-2.8 fl. oz.


Soybeans 30% or more defoliation prebloom or 20% or more defoliation bloom to pod or 5-10% of

pods damaged

Grasshopper control in soybeans


material/Acre

*Asana XL 5.8-9.6 fl. oz.

*Baythroid 2 2.1-2.8 fl. oz.

Dimethoate see product label

*Furadan 4F 1/4 -1/2 pt.

*Lorsban 4E 1/2-1 pt.

*Mustang Max 3.2-4 fl. oz.

*Penncap-M 2-3 pt.

*Warrior with Zenon

Technology 3.20 to 3.84 fl. oz.

*Designates a restricted use pesticide. Be sure to follow all label directions, restrictions and precautions.



*Furadan 4F 1/4-1/2 pt.



*Warrior with Zenon Technology 2.56 to 3.84 oz.



Corn 7 or more nymphs or adults

present per square yard and foliage

or grain is being severely damaged

Grasshopper control in corn

Insecticide Rate of formulated material/Acre

*Asana XL 5.8-9.6 fl. oz.

*Capture 2.1-3 fl. oz.





*Penncap-M 2-3 pt.


Sevin 4F 1-3 pt.

Sevin XLR Plus 1-3 pt.

*Warrior with Zenon Technology 2.56 to 3.84 fl. oz.



Alfalfa and clovers 3-7 or more nymphs or adults present per square yard

Grasshopper control in alfalfa and clovers


*Baythroid 2 2-2.8 oz.

Dimethoate see specific label


Imidan 70-W 1-1 1/3 lb.



*Penncap-M 2-3 pt.


Sevin 80S 2/3-1 7/8 lbs.


*Warrior with Zenon Technology 2.56-3.84 fl. oz.



Wheat and small grains (in fall) 8 or more nymphs or adults present per square yard

Grasshopper control in wheat and small grains



*Furadan 1/4-1/2 pt.

*Lorsban 4F 1/2-1 pt.


Sevin 4F 1-3 pts.


*Warrior with Zenon Technology 2.56 to 3.84 oz.


Note: see specific insecticide labels for control of grasshopper infestations in wheat, oats, barley and rye crops.


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