Hadrotettix trifasciatus (Say)
Wyoming Agricultural Experiment Station Bulletin 912
Species Fact Sheet
by Robert E. Pfadt
Geographic range of Hadrotettix
Click here for the printable version
The threebanded grasshopper ranges widely in the grasslands of the
West. It is a common species of the shortgrass, desert, and mixedgrass
prairies. It is less abundant in other prairies and is rare in grass-shrub
communities of the intermountain basins. In the tallgrass prairie
it occupies areas of sparse vegetation on gravelly hilltops and slopes.
to Top of Page
Because of its low densities in most western grasslands, the threebanded
grasshopper does not appear to be of great economic importance either
as a damaging pest or as a beneficial insect. Its feeding on good
forage grasses would tend to give it pest status, but research has
shown that it feeds more heavily on poor forage plants and plants
poisonous to livestock (death camus, milkweeds, some milkvetches,
and others). The threebanded grasshopper is one of the largest rangeland
species. Live weight of males and females collected from the mixedgrass
prairie of eastern Wyoming averaged 540 and 1,654 mg, respectively
(dry weights 152 mg and 469 mg, respectively).
to Top of Page
The threebanded grasshopper is a polyphagus species feeding on
grasses, forbs, sedges, dead and weakened insects, plant litter,
and dry cattle dung. It feeds chiefly on forbs, with as many as
40 species recorded from analyses of crop contents and direct observations
in nature. Examination of 152 specimens collected from several habitats
near North Platte, Nebraska revealed that 75 percent of crop contents
consisted of forbs, 21 percent grasses and sedge, and 4 percent
arthropod parts. Of the 18 forbs identified in the crops, scarlet
globemallow was most abundant (8 percent). The next most abundant
were a group of four species, each contributing 4 percent to crop
contents: Missouri milkvetch, Virginia pepperweed, scarlet gaura,
and breadroot scurfpea. Two grasses (western wheatgrass and blue
grama) and one sedge (threadleaf sedge) each comprised 4 percent
of the crop contents.
In multiple-choice tests, F. B. Isely, an early investigator of
grasshopper biology, found that the threebanded grasshopper preferred
antelopehorns, milkweed, and narrowleaf bluet. As these plants grow
in the optimum habitat of the grasshopper in northeastern Texas,
he concluded that they were its host plants.
Several observations have been made of the threebanded grasshopper's
method of feeding. A hungry grasshopper crawling on the ground often
stops to feed on ground litter. This litter may consist
of green or dry grasses, forbs, or dead insects. An interesting
observation was made of a female H. trifasciatus and a male
Aulocara elliotti that came across a dead adult grasshopper
(Trachyrhachys kiowa) at nearly the same time. In the scramble
that followed, the larger female won out and fed for approximately
eight minutes on the cadaver before it was inadvertently frightened
Another female climbed 2 inches up a short forb stem, cut a 1 inch
section, held on to it with the front tarsi, and then consumed it
completely in approximately five minutes. This grasshopper then
fed briefly on the stub and finally walked away.
An observation was made of a caged female feeding on a dandelion
leaf. It perched diagonally on the leaf and fed on the leaf's edge.
In a series of progressive ingestions it moved its head forward
1/4 inch on the edge and then ate back this distance. Dandelion
appeared to be a relished food plant, but it is a rare species in
the habitat of this grasshopper.
to Top of Page
The threebanded grasshopper is a strong flier, possessing long
wings that usually extend 6 to 10 mm beyond the end of the abdomen.
Finding "accidentals" of the species in three Colorado
mountain sites at altitudes of 6,700 to 10,000 feet provides evidence
that it makes dispersal flights. The site of the highest elevation
was 10 miles from the nearest known resident population.
Flushed flight is usually straight with a 90 degree turn at the
end. Landing is soft as they normally flutter to the ground. Crepitating
in flight, males travel distances of 9 to 24 feet and the heavier
females 6 to 15 feet, both at heights of 12 to 18 inches. Flying
with the wind (2 to 8 mph), a male was observed to travel a distance
of 42 feet. A case of mass emigration of adults from a desert prairie
site on the San Carlos Apache Indian Reservation, Arizona occurred
during June 1980. A dense infestation of grasshoppers, 36 per square
yard, was recorded on May 30, 1980 in which the following grasshoppers
(mainly ultimate instars) dominated: Melanoplus cuneatus
(14 per square yard), Aulocara elliotti (13 per square yard),
Melanoplus sanguinipes (4.4 per square yard), and Hadrotettix
trifasciatus (3.8 per square yard). Sampling the site on June
26 revealed that the densities of adult grasshoppers were: Aulocara
elliotti 15 per square yard and Melanoplus cuneatus 2.5
per square yard. No Melanoplus sanguinipes and no adult
Hadrotettix trifasciatus were found. Only one ultimate instar
of the latter species was found in 50 1-square-foot samples. Circumstantial
evidence indicated that the forb feeders (all the adult Melanoplus
sanguinipes, all the adult Hadrotettix trifasciatus,
and 82 percent of the adult Melanoplus cuneatus) had emigrated
from the site, ostensibly because of food shortage. The population
of Aulocara elliotti, which uses grasses for food, remained
high at 15 adults per square yard.
to Top of Page
Figures 1-4. Appearance
of the five nymphal instars, their sizes, structures, and
color patterns. Notice progressive development of wing pads.
BL=body length, FL=Hind Femur Length. AS=number of antennal
First Instar: BL 5.2-10.4 mm FL 3.9-4.4 mm AS 13-14.
Second Instar: BL 7.9-12.5 mm FL 5.1-6.4 mm AS
Third Instar: BL 12-16.7 mm FL 7.8-9.1 mm AS 20-21.
Fourth Instar: BL 19.5-22.5
mm FL 10.9-13 mm AS 23.
Figures 5-9. Appearance
of the adult male and female, wing, leg, and eggs.
BL 24.5-27.5 mm FL 13.8-15 mm AS 23-24.
Adult Female: BL 28-35.5 mm FL 14.5-18.3 mm
Spread left wings of female.
Inner face of female, hind femur, tibia, and tarsus.
Egg pod and four loose eggs.
The threebanded grasshopper is a large rangeland species (Fig.
5 and 6). Antennae are long and dark, each segment often with a
light anterior annulus. Pronotum has the median carina very low.
Tegmen with three dark bands; hind wings with disk pale yellow or
nearly white, outer dark band wide and located in the distal third
(Fig. 7). Outer face of hind femur with an oblique dark band and
an adjacent, distal light band; inner face mainly dark blue, adjacent
distal light band, knee area dark blue; hind tibia orange or red
(Fig. 8). The distal light bands of the outer and inner face meet
and form a wide annulus around the hind femur.
The nymphs are identifiable by their color patterns, structures,
and shape (Fig. 1-4).
- Head with face vertical, antennae long and dark.
- Pronotum with low median carina, uncut in instars I and II,
cut near middle in instar III, cut in front of middle in instar
- Color patterns of hindlegs similar to adult, except hind tibia
of instar I often gray and tan.
- General body color brown or gray with dark brown spots.
to Top of Page
The threebanded grasshopper hatches early in the season along with
Ageneotettix deorum, Amphitornus coloradus, and Aulocara
elliotti. In the mixedgrass prairie of eastern Wyoming, eggs
usually begin to hatch during the latter part of May. In 1992, however,
first instar nymphs were collected on May 9, along with first and
second instars of Ageneotettix deorum and Amphitornus
coloradus. In the mixedgrass prairie of eastern Montana in 1950,
hatching of the threebanded grasshopper and A. coloradus
began on May 22. In the Southwest, hatching is earlier with first
instar nymphs present in early May.
to Top of Page
Development of the threebanded grasshopper begins with relatively
large nymphs. The length of the hind femur of first instars averages
4.3 mm; by comparison, that of Metator pardalinus, another
large bandwinged species, averages 3.6 mm.
Nymphal development of the threebanded grasshopper is relatively
long. Based on dates of observations of first instar nymphs and
of first adults, the length of the nymphal period was 56 days in
mixedgrass prairies of southeastern Montana in 1950 and southeastern
Wyoming in 1991. At the same site in Wyoming in 1992, the nymphal
period was 62 days. Because the nymphs appeared three weeks sooner
in 1992 than in 1991, they undoubtedly were exposed to lower temperatures
early in development, which extended the nymphal period six days.
Surprisingly, only four instars are needed by this large grasshopper
to reach the adult stage, as revealed by a study of the morphology
of field-collected nymphs (the shape and size of the ovipositor
and the wing pads, the length of the hind femur, and the number
of antennal segments). Although females of M. pardalinus
weigh only half as much as females of H. trifasciatus, the
former species requires five instars to complete development. A
comparison of these two species shows that nymphal, stepwise growth
(metamorphosis), as gauged by the increase in length of the hind
femur, of H. trifasciatus is greater than that of M. pardalinus.
Measurements of the hind femur of the first four female instars
of each species yield a growth factor of 1.43 for H. trifasciatus
and 1.31 for M. pardalinus. This difference and the beginning
larger size of first instars of H. trifasciatus readily account
for the heavier adults of this species despite its having only four
instars. Real growth (the daily increase in weight of nymphs) of
both species is probably similar, but because the nymphal period
of H. trifasciatus is longer, the adults become significantly
to Top of Page
Adults of the threebanded grasshopper usually remain in the same
habitat in which the eggs hatch and the nymphs develop. Their preferred
host plants remain green during the summer. However, if these plants
dry up or are exhausted by intensive grazing of grasshoppers, the
adults respond by emigrating and thereby finding, perhaps, a more
The adults appear in mid June in the shortgrass prairie of southwest
Texas and the desert prairie of Arizona and a month later in the
mixedgrass prairie of Montana and Wyoming. Although aggregating
rituals of the sexes have not been seen, courtship has been observed
several times. Males approaching a female may make tipping motions
of the hind femora. As they come closer, they stridulate to attract
her attention. Successful courtship has not been noted, but rejection
by the female has been observed. Females may reject courting males
by hopping away, raising the hind femora and holding the tibiae
over the back while making slight upward kicking motions, tipping
the hind femora, or kicking out with the hind tibiae.
Oviposition begins about one month after the fledglings appear.
Females retreat into grass cover, often blue grama or buffalograss,
and oviposit through plant litter into the ground. An interesting
observation was made in the mixedgrass prairie of southeastern Wyoming
of a female preparing an oviposition site. She crawled into a secluded
spot among blue grama, then tipped the front of her head down and
began to fashion a small depression in plant litter by bobbing her
head up and down into the litter. After a few seconds she turned
around and began to work her ovipositor into the depression, but
was soon frightened by the observer attempting a closer look.
In the saltbrush-bunchgrass community of the Big Horn Basin (Big
Horn County, WY) where bare ground prevails, a single observation
was made of a female ovipositing in bare ground 2 inches southeast
of a saltbrush. She was discovered at 12:12 p.m. DST with her ovipositor
already inserted into the soil. She completed her laying between
12:45 and 12:50 p.m. but was not observed extracting her ovipositor
nor covering the hole. Temperature of the soil surface ranged from
113° to 117°F and the air at the 1 inch level from 78° to 81°F.
The sky was clear, the soil dry, and an east wind ranged from 0
to 6 mph. An examination of the position of the pod in the soil
revealed that the top of the pod was 1/8 inch below the
soil surface, the froth occupied 5/8 inch of the pod, was vertically
oriented. Because of the sharp curve in the pod, the egg portion
lay horizontally in the soil so that the eggs were oriented almost
vertically. The eggs were at a depth of 1/2 to 3/4 inch.
The egg pod of the threebanded grasshopper is 1 inch long and strongly
curved (Fig. 9). The egg section is 5/8 inch long and contains from
18 to 26 eggs. In Figure 9 the loose eggs are recently laid and
tan, and those in the intact pod are older and have turned reddish-brown.
Eggs are large, their lengths ranging from 7.2 to 8.7 mm.
to Top of Page
The center of distribution of the threebanded grasshopper appears
to be in the Southwest's shortgrass and desert prairies. Although
absolute densities were not determined, a study (1966-72) of grasshopper
populations in the shortgrass prairie of the Texas Panhandle revealed
that in two of the years (1970 and 1971) the threebanded grasshopper
was the dominant species. In the other years Mermiria picta
or Syrbula admirabilis was dominant. In the desert prairie
of Arizona, the threebanded grasshopper occurs at densities of 1.3
to 4 per square yard and often ranks fourth in abundance after Aulocara
elliotti, Melanoplus cuneatus, and Melanoplus sanguinipes.
In the extensive mixedgrass prairie of the West, the threebanded
grasshopper is a common but not abundant species. Densities range
from less than 0.1 to 0.3 grasshoppers per square yard. These low
densities persist from year to year and do not appear to track the
dynamic fluctuations of the dominant species or the assemblage.
to Top of Page
The threebanded grasshopper is a ground-dwelling species. At night
it rests horizontally on the ground surface surrounded by a canopy
of grasses. When the rays of the sun strike them, about two hours
after sunrise, both nymphs and adults begin to bask. They sit horizontally
on the ground and turn a side perpendicular to the sun and lower
the flexed hindleg to expose the abdomen. Basking may last for two
hours, until soil temperatures have risen to 80°F and air temperatures
(1 inch high) to 72°F. Activities such as walking and feeding then
begin. A mating pair was observed at 11:55 a.m., and attempts by
two males to mate with a single female were noted at noon. Neither
attempt was successful, although the female made no effort to dislodge
them after they had mounted. A female was observed testing sites
for oviposition in litter under a grass canopy at 12:42 p.m., when
bare soil registered 130°F and air temperatures 95°F. Adults usually
take evasive action from excessive heat when soil temperature reaches
120°F. Adults first stilt and then crawl away from hot bare ground.
They evade the extreme heat by sitting on thick litter or by crawling
atop blue grama. In either case they become elevated approximately
2 inches above ground. With further increase in temperature they
may crawl into shade of vegetation or crawl up a plant to a height
of 3 inches.
Few observations of the threebanded grasshopper were realized between
1 p.m. and sunset. At 5:40 p.m. a male and a female were discovered
sitting horizontally and quietly on bare soil under a cloudy sky.
Although still unknown, the threebanded grasshopper during clear
weather probably basks before moving to its night resting locations.
to Top of Page
Alexander, G. and J. R. Hilliard, Jr. 1969. Altitudinal
and seasonal distribution of Orthoptera in the Rocky Mountains of
Northern Colorado. Ecological Monographs 39: 385-431.
Anderson, N. L. and J. C. Wright. 1952. Grasshopper
investigations on Montana range lands. Montana Agr. Exp. Stn. Bull.
Daniels, N. E. and L. D. Chedester. 1973. Grasshopper
collections on three land types. Texas Agr. Exp. Stn. MP-1100.
Isely, F. B. 1938. The relations of Texas Acrididae
to plants and soils. Ecological Monographs 8: 551-604.
Joern, A. 1979. Resource utilization and community
structure in assemblages of arid grassland grasshoppers (Orthoptera:
Acrididae). Trans. Amer. Entomol. Soc. 105: 253-300.
Otte, D. 1970. A comparative study of communicative
behavior in grasshoppers. Univ. Michigan Mus. Zool. Misc. Publ.
to Top of Page