Grasshoppers

Grasshoppers, permaculture

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Insects
Extension
Grasshoppers
Frank A. Hale, Professor
Jaime Yanes Jr., former Assistant Professor
and Harry E. Williams, former Professor Emeritus
Extension Entomology and Plant Pathology
Grasshoppersmayattimesbecomeseriouspests
on ornamentals, vegetable and ield crops. Grasses and
otherherbaceousplantsarethemostcommonfoodfor
thesepests,butafterthosehostsare
consumedthegrasshoppersoften
turn to feeding on vegetables, ield
cropsoronleavesandeventender
bark of shrubs and trees.
Jack Parker, Knoxville
University of Tennessee
Femaleslayeggsinthesoilinelongated,1-to3-
inch masses in late-summer and fall. Eggs are usually
depositedingrainstubble,fencerows,ditchbanks,
roadsides and meadows. The egg is the overwintering
stage. Hatching occurs in the spring as early as late
February. Young nymphs (immatures) search for food
in the immediate area. The grasshoppers are forced to
migratetootherfoodsourcesastheybecomelargerand
deplete their host plants in the area.
Grasshoppers mature into adults in 40 to 60 days.
Mating takes place and the females begin laying eggs.
Oviposition (egg-laying) continues for nearly three
monthsduetothedifferencesinhatchingtimeand
developmental rate. A single female may lay from 200
to 400 eggs over a period of several weeks.
Afteroviposition,adults
continuetofeeduntilcold
weather kills them. Some
speciesmayhavemorethanone
generation a year in Tennessee.
Variationsinpopulationlevels
of grasshoppers are inluenced
by the environment. High
Description
Adultgrasshoppershaveshort,
thread-likeantennae;chewing
mouthparts;enlargedhindlegsthat
arespecializedforjumping;narrow
frontwings;andbroad,fan-like
hindwings.
Life Cycle
Mostgrasshopperswillmateand
live in the same area during the year.
Somespeciesmayhavesuchalarge
increaseintheirpopulationthatthey
are forced to leave the breeding area.
Edward L. Manigault,
Clemson University Donated Collection,
www.insectimages.org
SP290-X
mortalitywouldfollowaseasonsuchasthis:warm
springweathercausingprematurehatchingofeggs,
followed by cooler temperatures (preventing normal
growth); a brief period of hot weather (favorable for
grasshopper diseases); and a cool summer and early fall
todelaymaturityandtoreducethetimeneededtolay
eggs. A series of warm, dry seasons favor grasshopper
outbreaks.
treat the crop you are trying to protect.
The insecticides carbaryl (Sevin
®
) or malathion
are approved for most garden and ield crops. These
three insecticides plus cyluthrin (Tempo
®
), bifenthrin
(Talstar
®
), deltamethrin (DeltaGard
®
) and lambda-
cyhalothrin (Scimitar
®
) can be used on lawns and many
ornamentals. Chlorpyrifos (Dursbanâ„¢) can be used on
golfcourses,sodfarms,roadmediansandindustrial
plant sites, but not in residential landscapes. Contact
your local county Extension ofice for grasshopper
control recommendations on speciic host plants.
BaitscanbemadebycombiningSevin
®
XLR Plus
(see label) with a cereal grain substrate (cereal grains
or their by-products, such as laky wheat bran, rolled
wheat, rolled oats and/or barley or oat millings) to
make a carbaryl bait containing 2 to 10 percent active
carbaryl. These carbaryl baits are most effective when
spreadovermowedorbarrenareasbetweenthecrop
being protected and the hatching beds. The hatching
bedsarethegrassyareas,particularlywithsouthern
exposureandmoresandysoilinwhichgrasshoppers
tend to lay most of their eggs. A bait of wheat bran
and
Nosema locustae
(Semaspore Baitâ„¢), a protozoan
thatisonlytoxictograsshoppers,canbeapplied
to the hatching beds. Semaspore Baitâ„¢ should kill
abouthalfofthegrasshoppersandinfectmostofthe
remainder. The infected survivors do not eat much
and the few eggs they lay are infected. If cannibalized,
they can infect other grasshoppers. The protozoan can
overwinter in infected egg cases and cadavers.
Control
Naturallyoccurringenemiesreducegrasshopper
populations. Eggs of certain insects, such as ground
beetles, blister beetles and bee lies, are laid in the soil
near overwintering grasshopper eggs. Studies have
shownthatthelarvaeofthesepredatorscandestroy
upto60percentofgrasshoppereggmasseslaidina
large area. Numbers of mammals, birds and predatory
insects feed on grasshoppers. Certain environmental
conditionsmayfavorthemultiplicationofnaturally
occurringmicroorganismsandthesubsequentinfection
of grasshoppers.
When natural controls are not suficient,
insecticidal control may be needed. An important factor
totakeintoconsiderationinobtaininggoodcontrolof
grasshoppersisthattheyoftenmoveinfromadjacent
roadsides, fencerows and pastures. In these cases, it
maybenecessarytotreattheareasadjacenttothecrop
to adequately protect it from migrating grasshoppers.
In other words, if large numbers of grasshoppers are
movingintoyourcropfromadjacentareas,itisoften
moreimportanttotreatthesurroundingareathanto
Precautionary Statement
To protect people and the environment, pesticides should be used safely. This is everyone’s responsibility, especially the user. Read
and follow label directions carefully before you buy, mix, apply, store or dispose of a pesticide. According to laws regulating pesticides,
they must be used only as directed by the label. Persons who do not obey the law will be subject to penalties.
Disclaimer Statement
This publication contains pesticide recommendations that are subject to change at any time. The recommendations in this
publication are provided only as a guide. It is always the pesticide applicator’s responsibility, by law, to read and follow all current
label directions for the speciic pesticide being used. The label always takes precedence over the recommendations found in this
publication.
SP290X 07-0015
Programs in agriculture and natural resources, 4-H youth development, family and consumer sciences, and resource development.
University of Tennessee Institute of Agriculture, U.S. Department of Agriculture and county governments cooperating.
UT Extension provides equal opportunities in programs and employment.
Useoftradeorbrandnamesinthispublicationisforclarityandinformation;itdoesnotimplyapprovaloftheproducttothe
exclusion of others that may be of similar, suitable composition, nor does it guarantee or warrant the standard of the product. The
author(s), the University of Tennessee Institute of Agriculture and University of Tennessee Extension assume no liability resulting
from the use of these recommendations.
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