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Pasture and Rangeland Insect Spraying
Grasshoppers
Chemical Application
Insecticides 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.
Barrier Treatment
Ranchers also may need to consider protection-spraying "barriers"
around valuable forage production areas such as highly productive hay
meadows or seeded crops such as 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. Spraying at two- or
three-week intervals may be necessary to protect these valuable forage
resources.
 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
short grass prairie are least likely to experience defoliation-induced
drought because low infiltration rates limit the depth of soil moisture
on these sites.
Life Cycle
There are three stages in the grasshopper life cycle - the egg, nymph,
and adult. The number of egg pods deposited by a single female may
range from 7 to 30 with 8 to 30 eggs per pod, depending on the species.
The eggs are well insulated with a frothy, sticky substance that is
excreted when eggs are deposited, and allows them to survive extremely
cold temperatures. Some grasshoppers prefer to lay eggs in soil
surrounded by grass roots, while other species select open areas with
accumulations of surface debris.
Most grasshoppers overwinter in the egg stage, but a few species
hibernate as 3rd instar nymphs. Most of these species are "band-wings,"
large grasshoppers seen early in the spring that make a crackling noise
during flight, but one, the
velvet striped grasshopper is a small, slantface grass feeder. These
species are normally few in number and do not seriously damage
rangeland. However, occasionally a serious infestation of these
over-wintering species causes heavy range damage.
Hatching time (late May and June) is influenced by weather and can be
predicted by grasshopper specialists by correlating the four
developmental stages of
over-wintering eggs (clear, coagulated, eye spot, and segmented) with
soil temperatures. Most nymphs start feeding within one day after egg
hatch and usually feed on the same plant
species as the  adult.
Young nymphs are the most vulnerable to weather conditions, diseases,
predators, parasites, and insecticides. Grasshopper nymphs generally develop to
the adult stage in six to eight weeks. Grasshoppers begin egg-laying
one to three weeks after becoming adults. They may live two months or
longer, depending on late summer and early fall weather.
Barrier
treatment with the A1 Mist Sprayer is the most cost effective way to
eliminate aphids, bean leaf beetles, bean aphids, grasshoppers, leaf
hoppers, ear worm, corn borer, boll weevils, stink bugs, and other
insect pests. A1 Mist Sprayer's high and low volume mist sprayers
create smaller mist size particles in a 0 to 140' air stream that stays
low to the ground for the best control and uniform coverage; Over,
Under and Around Plant Foliage.
Spray your crops directly and spray roadside ditches, waterways,
fencerows, field perimeters and hard to reach areas using 1/10th the
water and less chemical!
This information is derived from Nebraska Cooperative Extension
NF02-328 (Revised May 2004) NebFacts.
A1 Mist Sprayer Resources
your Pasture
and Insect/Vector Control Specialists!
Continental Wholesale
LLC
15 5th Ave S.E.
Hampton IA 50441
Phone 641-456-3165 · Fax 641-456-2406
US Toll Free 800-869-7203
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