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The redwinged grasshopper ranges widely in North America occupying grass and grass-shrub habitats. It reaches highest densities in the mixedgrass prairie. At the periphery of their geographic range, these grasshoppers occupy restricted habitats and are less numerous. In the tall and midgrass prairies of their eastern and northern range, they inhabit the dry, sandy, or gravelly uplands and hilltops, while in their western and southwestern range, they inhabit mesic grassland sites.
Observations in a Montana habitat of the mixedgrass prairie revealed that nymphs spend much time on grass plants and consume green leaves of downy brome, western wheatgrass, blue grama, sideoats grama, needleandthread, and green needlegrass. The adults were observed to spend little time on plants and showed a preference for junegrass.
In laboratory two-choice tests, adults fed sparingly on dandelion and heavily on downy brome and western wheatgrass. In these tests the grasshoppers fed more heavily on young wheat leaves then on either downy brome or western wheatgrass.
The redwinged grasshopper's method of attacking a grass plant has been observed twice in nature and several times in the laboratory. One observation in nature involved the feeding of a female (instar V) on two felled green leaves of needleandthread. Crawling on the ground, the nymph contacted the first leaf (2.5 inches long) at 8:52 a.m., and consumed it entirely from base to tip. As it fed, the nymph handled the leaf with its front tarsi and rested horizontally on the ground. At 9 a.m. it contacted the second leaf, also 2.5 inches long, and ingested it by 9:03 a.m. Ground temperature was 76°F, air 68°F, sky was clear, and a southwest wind prevailed at 0-4 mph.
The second observation was of a male that flew appetitively. Upon landing it walked 2 inches, then in a diagonal orientation with hindlegs on the ground it began to feed on a leaf of grama grass, and then on the grazed end of a leaf of needleleaf sedge. The male finally turned head-down and continued to feed on the sedge. Feeding occurred from 10:33 to 10:38 a.m. DST at soil temperature of 75°F and air 67°F, clear sky, and a south wind of 2-5 mph.
Feeding on felled leaves was observed also in a laboratory terrarium provisioned with transplant of mixedgrass prairie. In addition, the adults fed on attached, recumbent leaves of needleandthread by devouring the leaf from the distal end to the base. Adults also reached with their mouthparts to feed on standing attached leaves. They attacked the leaf from 1/8 to 1 inch above its base, cut through it while feeding, then held onto the detached section, and consumed it completely. If the detached section was dropped, the grasshopper often found it and continued to feed.
On warm, sunny days, the redwinged grasshopper makes many voluntary or appetitive flights. In the mixedgrass prairie of southeastern Wyoming the grasshoppers have been observed to fly distances of 1 to 12 feet at heights of 3 to 12 inches. Interesting displays of flight by males have been observed in the grass-forb habitat of the George Reserve. Although most flights are in a straight line, some males fly nearly straight up to a height of approximately 4 feet, and then flutter down slowly with their wings flashing brilliantly red in the sunlight. When they reach the vegetation canopy, they close their wings and drop to the ground. The performance is accompanied by a loud crackling crepitation. This flight behavior as well as appetitive straight flight are exhibited only when the sun is shining brightly. The flights function to bring pairs together for courtship and mating.
Little information is available on dispersal and migration by the redwinged grasshopper. Adults have been found as accidentals at 10,000 feet in the mountains west of Boulder, Colorado, indicating dispersal of 14 miles from the closest resident population.
On 27 September 1993, a collection of seven species of rangeland grasshoppers was made along a sidewalk in downtown Cheyenne, Wyoming. Six male and three female specimens of the redwinged grasshopper were represented in the collection, which also included a total of 17 males and 23 females of Melanoplus gladstoni, the most abundant of the seven species. The collection suggests dispersal of these species from a heavily infested rangeland site of the mixedgrass prairie surrounding Cheyenne. Dispersal of individual adults also occurs, as indicated by the finding of a female on a sidewalk of the campus of the University of Wyoming, Laramie, on 14 September 1992 and a male on a sidewalk of the campus of Colorado State University, Fort Collins, on 9 September 1993.
In Michigan, Wisconsin, and Minnesota some demes (local populations) consist entirely of yellow-winged individuals. West of these states all individuals possess bright red wings.
The nymphs (Fig. 1-5) are identifiable by their shape, external structure, and color patterns.
1. Instar I. Head conspicuously large and rounded; segments of maxillary and labial palps fuscous, only tip of terminal segment yellow. General body color black. Pronotum with low, entire median carina; lateral lobe black with a few scattered gray or brown spots. Hind tibia dark red; hind tarsus black on first segment and distal two-thirds of last segment with middle yellow or pale green.
2. Instar II and III. Head rounded, face nearly vertical, lateral foveolae triangular or quadrilateral; segments of maxillary and labial palps fuscous, each segment with tan or brown annulus apically. Pronotum with low median carina, weakly incised and with disk tectate (rooflike); lateral lobes of pronotum brown and fuscous. Venter of thorax and abdomen usually shiny black. Hind tibia dark orange, fuscous at both ends; hind tarsus black at both ends and yellow in the middle.
3. Instar IV and V. Head elongated vertically, not as rounded as in earlier instars; lateral foveolae triangular or quadrilateral; segments of maxillary and labial palps fuscous, each segment with yellow annulus apically. Pronotum with low, uniformly elevated median carina incised once in front of middle; disk of pronotum tectate. Color of body dull brown and black; venter of thorax and abdomen solid, shiny black; hind tibia multicolored (fuscous, dark orange, and tan).
Although this species and the specklewinged grasshopper, Arphia conspersa, are considered late-hatching grasshoppers, the redwinged grasshopper hatches a month earlier than the specklewinged. Hatching of the redwinged continues for two weeks. A laboratory study has shown that after deposition, eggs develop to stage 19 (50 percent of embryonic development) and then enter diapause. Held at 77°F the eggs reached this stage in 30 days. Available data suggest that eggs of the redwinged grasshopper pass the winter in stage 19 and then complete the remaining 50 percent of their development the following spring.
The act of oviposition was observed by Norman Criddle (1875-1933), an early student of North American grasshoppers, on 21 September and 1 October 1917 in Manitoba. Females rested on their front and midlegs and held the hind ones in the air, as egg laying took place. Two females were found ovipositing at the edge of an old trail. Because oviposition was underway when discovered, the total time of egg laying was not determined, but the females withdrew their abdomens after 26 and 33 minutes. They then brushed soil and litter over the aperture of the holes using the hindlegs both alternately and in unison. The recovered pods contained 24 and 25 eggs.
Caged females readily oviposit into bare soil. Two pods laid by females from the mixedgrass prairie of southeastern Wyoming contained 31 and 36 eggs. The pods are nearly straight and 1 5/8 inches long. The top 5/8 inch is occupied by froth, the bottom inch by eggs. Eggs are tan to brown and 4.2 to 5.2 mm long (Fig. 10).
In the shortgrass prairie of north-central Colorado (Central Plains Experimental Range), densities of young adults have ranged from 0.02 to 0.05 per square yard. In spite of low densities, populations persist from year to year. Whenever investigated on this experimental rangeland, the redwinged grasshopper has been a prominent member of the assemblage. Dates of confirmed occurrence include consecutive years from 1968-75 and from 1981-86. Research during the latter period showed that populations fluctuated annually and tracked the density of the entire grasshopper assemblage (Table 1).
In the Davis Range of Texas, Ernest Tinkham reported that the redwinged grasshopper was very abundant in the fall of 1928 and that large swarms flew up from tall grasses. Regrettably, he did not determine the absolute density.
Cantrall, I. J. 1943. The ecology of the Orthoptera and Dermaptera of the George Reserve, Michigan. Univ. Michigan Mus. Zool. Misc. Publ 54.
Criddle, N. 1918. The egg-laying habits of some of the Acrididae (Orthoptera). Canadian Entomol. 50: 145-151.
Capinera, J. L. and D. C. Thompson. 1987. Dynamics and structure of grasshopper assemblages in shortgrass prairie. Canadian Entomol. 119: 567-575.
Jurenka, R. A. 1982. Studies on the embryonic development and embryonic diapause in Arphia conspersa (Scudd.) and Arphia pseudonietana (Thomas) (Orthoptera: Acrididae) and the effects of plant growth hormones on reproduction and diapause. M. S. thesis, Montana State University, Bozeman, MT.
Otte, D. 1970. A comparative study of communicative behavior in grasshoppers. Univ. Michigan Mus. Zool. Misc Publ. 141.
Tinkham, E. R. 1948. Faunistic and ecological studies on the Orthoptera of the Big Bend Region of Trans-Pecos Texas. Amer. Midl. Nat. 40: 521-663.
Next Species in Subfamily: Camnula pellucida