Striped Sand Grasshopper
Wyoming Agricultural Experiment Station Bulletin 912
Species Fact Sheet
by Robert E. Pfadt
Geographic range of
Melanoplus foedus Scudder
The striped sand grasshopper, Melanoplus foedus,
ranges widely in western North America, nearly coextensive with the range of
Melanoplus packardii which it closely resembles. The habitats of these
two species within their common geographic ranges differ remarkably. The
striped sand grasshopper inhabits vegetated areas of sandy soils while the
Packard grasshopper inhabits vegetated areas of loamy soils. Both species feed
principally on forbs and both conduct most activities on the preponderant bare
ground of their habitats.
A distinctive community of native plants grows in sandy
soils. In addition to the widely distributed and tolerant grasses blue grama,
western wheatgrass, and needleandthread, two species of tall grass are
prominent, prairie sandreed and sand bluestem and one midgrass, sand dropseed.
Of the many forbs, western ragweed, several species of sunflower, and several
species of scurfpea are commonly present.
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Importance Because of its preference for "weeds" and its
normally low density in the assemblage of grasshoppers inhabiting sandy
rangeland sites, the striped sand grasshopper is of minor economic importance.
Nevertheless, damaging densities irrupt on the sandy rangeland of western Idaho
and eastern Oregon. This species also increases to outbreak numbers in weedy
land adjacent to crop land. After becoming adult the grasshoppers invade and
damage fields of wheat, barley, corn, and alfalfa. The Cooperative Economic
Insect Report recorded severe infestations in five states: Idaho, Nebraska,
Kansas, Oklahoma, and Texas.
In western Idaho an assemblage of species,
mainly Melanoplus sanguinipes, M. bivittatus, and M.
foedus, irrupted in 1957 reaching densities of 100 per square yard. In
eastern Idaho in 1961, the striped sand grasshopper increased along roadsides
to numbers averaging 8 per square yard. In 1958 in southwestern Nebraska, an
assemblage of species, mainly Melanoplus sanguinipes, M.
angustipennis, and M. foedus, infested margins of wheat fields at
densities of 5 to 54 per square yard. No follow-up reports were made of this
infestation. Presumably the grasshoppers were either controlled or they
dispersed into the wheat and caused damage.
As no quantitative study of
this grasshopper's impact on rangeland and crops has been made, we may estimate
its importance based on its weight. It belongs to the largest third of North
American grasshopper species. Live weights of five males and six females
collected in sandy rangeland of southeastern Wyoming averaged 450 and 725 mg,
respectively (dry weight: males 143 mg, females 238 mg).
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The striped sand grasshopper is a highly polyphagous species that feeds on a
variety of forbs, grasses, and sedges. Fifty-six species of forbs, 19 species
of grasses, and 2 species of sedges have been detected in crop contents of
specimens collected from sites in four states. Table I shows the common food
plants of grasshoppers collected in Colorado, Idaho, Nebraska, and North
Dakota. Crop analyses of specimens captured in two rangeland sites in
southwestern Idaho revealed that common plants ingested were downy brome,
thickspike wheatgrass, sunflower, redstem filaree, tumblemustard, and western
salsify (Tragopogon dubious). Two-choice laboratory tests of striped
sand grasshoppers from Wyoming showed that dandelion and green young wheat are
also among its preferred food plants.
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Migration and Dispersal
The striped sand grasshopper is a long-winged species with
good capacity for flight. Adults observed in Idaho are wary and commonly fly 30
to 60 feet when disturbed. In this state during the dry period of summer when
upland vegetation desiccates, the adults move into more mesic, ravine habitats.
Movement of adults from weedy rangelands, CRP land, and field margins into
crops have been reported in three western states - Idaho in 1957 and 1961,
Texas Panhandle in 1959, and Oklahoma in 1973. The details of these dispersals
were not investigated and mass migrations have never been
Observations of flushed flight in sandy native grasslands of
southeast Wyoming, indicated shorter distances than in Idaho. Flight distances
were 2 to 9 feet at heights of 4 to 10 inches. The flights were straight and
silent with the landed grasshoppers facing in the direction of
The nymphs have not been observed to disperse extensively or to
migrate. Apparently they complete nymphal development in the habitat of their
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Appearance of the five nymphal instars of Melanoplus foedus, their
sizes, structures, and color patterns. Notice progressive development of the
small wing pads. BL = body length, FL = hind femur length, AS = number of
Fig. 1, First Instar:BL 5.4 mm FL 3.2 mm AS
Fig. 2, Second Instar:BL 5.7-7.8 mm FL 3.4-4 mm AS
Fig. 3, Third Instar:BL 8-13.1 mm FL 5.8-8.4 mm AS
Fig. 4, Fourth Instar:BL 14-16 mm FL 9.5-10.5 mm AS
Fig. 5, Fifth Instar:BL 18.2-20.2 mm FL 12-13.5 mm AS
6-10,Appearance of the adult male and female of Melanoplus foedus,
dorsal view of head and pronotum, cercus of the male, egg pod and
Fig. 6, Adult Male:BL 25-28
mm FL 13.5-14.8 mm AS 25-27.
Fig. 7, Adult Female:BL 26-35 mm FL I4.5-17.5 mm AS
Fig. 8, Dorsal view of head and pronotum of a
Fig. 9, End of male abdomen showing cercus, furcula, and
Fig. 10, Egg pod and
three loose eggs.
The striped sand grasshopper is a large,
usually colorful species equaling in size and resembling in color patterns the
closely related Packard grasshopper, Melanoplus packardii. A broad brown
band runs down the top of head and center of the pronotum, On each side of this
band is a pale yellow stripe (Fig. 8) to which the common name refers.
Variations in color, however, occur among populations of adult striped sand
grasshoppers. In the sandy sites of eastern Wyoming and Colorado adults are
bright yellow and brown with contrasting bars and stripes (Fig. 6 and 7); in
the rangeland of eastern.
Oregon, adults are dull pale tan with faint
bars and stripes. The wings are long and extend 1 to 4 mm beyond the apex of
the hind femora. Tegmina are usually unspotted. The outer medial area of the
hind femur is either solid fuscous or pale yellow and spotted fuscous; the
inner medial area is bright yellow. In Wyoming and Oregon the hind tibia is
usually red but farther north it is blue. As the striped sand grasshopper and
the Packard grasshopper are superficially alike, definite identification
depends on differences of the aedeagus. The valves of the Packard grasshopper
are equally short; the outer valve of the striped sand grasshopper is short,
the medial valve is long, clearly extending beyond the tip of the outer valve
The nymphs are identifiable by their structures, color
patterns and shape (Fig. 1-5).
- Head with face nearly vertical, color green, sparsely
spotted fuscous, spots more numerous on top and front of head; compound eye
with relatively large tan spots; antennae filiform and predominantly
fuscous,each segment ringed anteriorly pale gray.
- Pronotum mostly green, disk of pronotum green or pale tan
and spotted fuscous, lobes unspotted or sparsely spotted.
- Outer medial area of hind femur green with three rows of
spots or nearly spotless; hind tibia pale green or pale gray.
Apparently the color of nymphs varies, as those collected in
Colorado and Wyoming are green, while those found in western Idaho are
predominantly pale brown or tan and only a few are green. Because of the
difficulty of separating nymphs of M. foedus from M. packardii
one may tentatively call nymphs collected in sandy soil M. foedus and
then return later to the site to capture adult males for confirmation using the
distinguishing structure of the aedeagus.
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The striped sand grasshopper is an early hatching species.
Nymphs first appear about two weeks after Cordillacris occipitalis and
about the same time as Melanoplus sanguinipes. All three species often
occupy the same sandy soil habitat. In southeastern Wyoming (elevations 4,100
to 5,000 ft), hatching begins usually in mid May, however, actual dates of
hatching have ranged from May 1 to 29. After the first nymphs appear, hatching
continues for two weeks. In southwestern Idaho and in the sandhills prairie of
southeastern North Dakota hatching occurs in late May and early June.
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Nymphs develop in late spring when temperatures are mild and
cool-season grasses and forbs are still green and nutritious. In southeastern
Wyoming, the nymphal period lasts approximately 40 days from mid May to late
June. Based on initial appearance of instar I and first adults, the nymphal
stage has been estimated to range from 34 to 42 days. In the sandy study site 5
mi south of Guernsey, Wyoming, calculated nymphal periods were 34 days in 1975
and 1981, 37 days in 1977, and 42 days in 1979.
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Reproduction In sandy soil habitats of southeastern Wyoming,
adults are present during the summer months from late June through September.
In favorable rangeland sites, they appear to remain lifelong, but whenever the
habitat deteriorates due to drought, they move to nearby areas with green
vegetation such as swales, ravines, and irrigated land.
studies of maturation, courtship, or fecundity of this grasshopper have been
made. A few field observations have been noted that provide incidental
information. In a study site in northeast Laramie County, Wyoming on 18 August
1999 at 8:17 am DST (soil 81°F, air 76°F, sky clear), a male made
courtship overtures of femur shaking as he faced a female 6 inches away. Before
the male could make contact, the female was frightened away by an inquisitive
cowboy on horseback.
In a study site 5 miles west of Torrington,
Wyoming, a female was observed on 27 July 1991 at 11:24 am (soil 120°F, air
86°F, sky clear) to begin boring into bare ground but after 1 minute she
ceased and walked away. The number of days from fledging to this ovipositing
behavior was estimated to be 26. In a study site of southeast Goshen County,
Wyoming, two females were observed ovipositing into bare soil at the side of a
ranch road on 25 August 1993 at 12:30 pm. In a study site south of Guernsey,
Wyoming, a female was discovered ovipositing into bare soil at 4:06 pm, 17
August 1990 (soil 101°F, air 86°F, sky clear).
with males in laboratory cages were provided plastic trays of sandy soil for
oviposition. The females readily found the sandy soil and deposited most eggs
into this medium. A few eggs however, were deposited on the screen floor of the
cage. One female was discovered ovipositing into the soil at 11:15 am on 3
August 1992. After removing her ovipositor from the soil she moved the end of
her ovipositor sideways and back and forth to brush soil over the exit
The pods contained from 16 to 30 tan eggs (Fig 10). Eggs were 4.8
to 5.1 mm long, the pods 1/2 to 3/4 inch long
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Ecology The striped sand grasshopper fluctuates in density
over the years much like other pest grasshoppers of the genus
Melanoplus. Recorded outbreaks usually consisted of several species in
the assemblage. Prominent coinhabitants include Melanoplus bivittatus,
M. sanguinipes, and M. angustipennis. The absolute density of
each species in these assemblages has not been reported. At times
M.foedus, essentially alone, may irrupt and become the sole cause of a
moderate outbreak. Such an outbreak occurred in 1961 in the vicinities of
Victor and Swan Valley, Idaho. The grasshoppers increased along roadsides to
densities averaging 8 per square yard.
In Wyoming native grassland,
densities of M. foedus have remained low, even during years of
outbreaks. In the longest studied site, a sandy soil habitat 5 miles south of
Guernsey, Wyoming, monitored for 12 years, 1975 to 1986, populations of M.
foedus fluctuated in density from less than 0.1 to 1.0 per square yard. At
its highest density of 1 per square yard M. foedus was subdominant to
M. sanguinipes which had risen to a density of 3.6 per square yard.
Populations of M. foedus in a study site of northeast Laramie County
have remained small with estimated densities of 1.3 per square yard for three
years, 1999 to 2001.
Over their large geographic ranges the two closely
related species M. foedus and M. packardii, do not, as a rule,
occupy the same habitats. Exceptions, however, occur. In the Pine Ridge of the
Nebraska Panhandle, pure populations of M. foedus were found on grass covered
ridges while at the bottom this species was often mixed with M.
Although how populations of the striped sand grasshopper
grow to outbreak densities remains undocumented, the reports of damaging
assemblages of grasshoppers in Idaho and Nebraska indicate that under
environmental condition fostering increases of other species of the genus,
especially M. bivittatus and M. sanguinipes which have been
studied thoroughly, M. foedus is similarly affected. By inference, mild
spring weather, adequate but gentle rainfall, a steady supply of preferred food
plants, few predators, and little disease all interact to promote population
growth of M. foedus.
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Activity At night in its native rangeland habitat, the striped
sand grasshopper shelters on the ground under canopies of grasses and forbs. In
disturbed weedy sites, however, it climbs tall plants such as kochia, Russian
thistle, sunflower, and sweet clover; it rests vertically, head up, usually on
the main stem, at heights of 12 to 24 inches.
In early August in
rangeland of southeast Wyoming, adults emerge from shelter and begin to bask 1
hour after sunrise (soil and air temperatures 50°- 60°F). They continue
basking for about 3 hours (at end of basking: soil 100°-110°F and air
80°-85°F). In basking they sit horizontally on bare ground and take a
flanking posture by turning a side perpendicularly to rays of the sun and
lowering the hindleg to expose the abdomen. On sunny days, adults spend most of
their morning basking, but during this period they also conduct other
activities. They have been observed to crawl, feed, court, and oviposit. They
discontinue basking at high temperatures but remain on the soil surface and
assume a variety of postures to reduce further insolation. As temperatures rise
still higher (soil 115°F air 95°F), the grasshoppers take evasive
action by climbing grass or forb stems to heights of 2 to 6 inches or they
crawl into the shade of vegetation. When temperatures ameliorate in late
afternoon, the grasshoppers resume daily activities. As temperatures cool still
further, they bask for a second time. Finally around sunset, they retreat to
their night time shelters.
The daily routine of activities of adults
roosting on tall plants is remarkably different from that of ground residents.
In the morning they bask by adjusting their positions on the plants and
adopting a flanking posture or a dorsal posture, remaining vertical, head up.
Later they feed on the host plant and when temperature of the habitat rises
above their preferendum, they adjust their positions on the plant. At times
they move to the ground, particularly for oviposition, but evidently also for
other purposes. In the site 5 miles west of Torrington, Wyoming, between 6 and
6:34 am on 26 July 1991, one adult was discovered on the ground while five
adults were found roosting on tall vegetation.
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Banfill, J.C. and M.A. Brusven. 1973. Food habits and
ecology of grasshoppers in the Seven Devils Mountain and Salmon River breaks of
Idaho. Melanderia 12: 1-21.
Hagen, A.F. 1970. An annotated list of grasshoppers (Orthoptera,
Acrididae) from the eleven panhandle counties of Nebraska. Nebraska Agr. Exp.
Stn. Research Bull. 238.
Joern, A. 1985. Grasshopper dietary
(Orthoptera: Acrididae) from a Nebraska Sand Hills prairie. Transactions
Nebraska Acad. Sci. 13: 21-32.
Ueckert, D.N. and R.M. Hansen. 1971. Dietary overlap of grasshoppers
on sandhill rangeland in northeastern Colorado. Oecologia 8: 276-295.
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