is a medium sized grasshopper species. It exhibits sexual dimorphism, with females being longer than males. Males measure at 16 to 20 mm, while females are 18 to 25 mm in length. These grasshoppers have a slanted face, and the antennae have 6 large, dark terminal segments that form a club, which give this species it's common name of "clubhorned". They are gray or green colored with markings on them. The side of the face has a dark streak on it from the bottom of the eye to the mandible, with an anterior vertical white band. Males have forewings that extend to or beyond the end of the abdomen, while females have much shorter forewings. The front tibiae is also thicker in males.
Nymphs resemble adults, though lacking wings and the antennal club. They are identifiable by their strongly slanted face, flat antennae, and the narrow light line behind the eye, which runs along the side of the head onto the body. The last two instars have erect wing pads, which the first two instars lack. Size increases regularly between molts. Clavate antennae are present as early as the second instar, but the inflated tibia of the male does not appear until the last molt. (Otte, 1981; Pfadt, 2002)
Acrididae have 5 instars). Development takes about 30 days in plains habitats, and about 42 days in alpine habitats. The first instar lasts no more than a week, while the last two instars probably last for longer periods of time. They are sexually mature 6 weeks after hatching. The accelerated development allows for adults to be present when grasses and sedges are still available during the short growing season. Males appear to mature earlier than females, and by the end of summer into fall, there are more females present than males. (Alexander and Hilliard Jr., 1964; Coxwell and Bock, 1995; Otte, 1981; Pfadt, 2002)is hemimetabolous. Eggs are laid in late summer, and enter diapause for the winter. In lower elevations, eggs hatch the following spring after one winter. In high elevation populations, eggs diapause for 2 or even 3 winters before hatching. Eggs hatch very early in the spring; there may still be snow and ice on the ground. Hatching occurs earlier at lower elevations. In plains habitats, they hatch in the first week of May, while in mountain areas, hatching begins in mid to late June. Hatching occurs over a period of 3 to 4 weeks, though individuals that hatch in July in alpine habitats often will not develop into adults before winter arrives. As an adaptation to boreal habitats, nymphal development is very quick, and has only 4 instars (most
There is little information available on the mating habits of (Pfadt, 2002). They are likely polygynandrous. Stridulation is likely a significant part of the courtship ritual, where the male vibrates the hind femur through a small arc against a vein on the tegmen, producing a "song" that females can use to identify possible mates of the same species.
Females oviposit amongst the roots of grasses or sedges. The eggs are light tan in color, 4.6 to 5.5 mm long, and are laid in pods. Each egg pod has 5 to 8 eggs, with the eggs in two rows. The pod is 10 to 13 mm long and 4 mm in diameter, and the pod is made up of a tan, hardened froth. The egg pods are oriented vertically in the soil or amongst clumps of grass. Multiple egg pods may be laid together in a single spot, and the same spot may used repeatedly, with new pods being laid on or even in old pods. The eggs enter diapause shortly after, and do not emerge until the following spring for prairie populations, or after two or three winters for alpine populations. Oviposition usually takes place during the late summer, from August until September in high elevation populations. There is one generation annually in plains habitats. (Coxwell and Bock, 1995; Hamrick and Hamrick, 1989; Pfadt, 2002)reaches sexual maturity in 4 to 6 weeks after hatching.
Females provide provisioning in the eggs, and also lay the eggs in an egg pod made of a hardened froth. The egg pods are placed in the soil at the roots of a clump of grass, providing protection. After this, the females leave the eggs and provide no further parental care. (Pfadt, 2002)
Orthoptera, stridulation is used to communicate between individuals. Males make a "song" by vibrating their back femur against the tegmina. Each species has its own unique sound, allowing individuals to identify their own species. Stridulation is likely used in the courtship process to communicate with possible female mates. (Pfadt, 2002)has compound eyes, allowing it to see its environment, as well as detect predators. It uses its antennae to identify food plants, by tapping its antennae, as well as its palps, on leaf surfaces. Sensilla on these parts detect chemicals and allow the grasshopper to find plants to eat. Physical touch elicits escape behaviors. As is characteristic of many
Clubhorned grasshoppers have eyes that let them see the environment around them, and also detect predators. They use their antennae and mouth parts to find food. By tapping their antennae and mouth parts on leaves, they can detect chemicals from the plant to determine if it is a plant they can eat. Physically touching the grasshoppers usually causes them to hop away to escape. To communicate with each other, males make a "song" by vibrating their back leg against their wing. Each species makes a different sound, which lets individuals find others of their own species, and also lets mates find each other. (Pfadt, 2002)
Clubhorned grasshoppers are herbivores, and feed mainly on grasses and sedges. Alpine populations also feed more on forbs than lower elevation populations. They have been recorded feeding upon 28 species of grass, and 6 species of sedge. Examinations of their crops have also found fungi, pollen, and arthropod parts. (Alexander and Hilliard Jr., 1964; Otte, 1981; Pfadt, 2002)
General predators of Horned Lark, Western Meadowlark, Chestnut-collard longspur, Sprague's Pipit, and White-Tailed Ptarmigan. Their gray and green coloration can serve as camouflage, though less in alpine habitats where vegetation and the opportunity for concealment is scarce. To escape from predators, these grasshoppers hop. Males also "prance", which is small, repeated hops without progression. Females are less active, and are less vigorous than males when escaping predators. (Coxwell and Bock, 1995; Kevan, et al., 1983; Maher, 1979; Pfadt, 2002)include birds, rodents, spiders, and predaceous insects such as ants. Prairie birds are significant predators, such as the
Spirura infindibuliformis, which infects ground squirrels. It can also be infected by the microsporidium protozoan, Nosema locustae, which can cause death, though usually only a very small percentage of the population is infected. (Anderson, et al., 1993; Ewen and Mukerji, 1979; Pfadt, 2002)serves as prey to birds, rodents, spiders, and other insects. It can be a significant herbivore, and can cause damage to several grass and sedge species when found in high densities. can be an intermediate host of the nematode
There are no known positive effects ofon humans.
has no special conservation status.
Angela Miner (author), Animal Diversity Web Staff, George Hammond (editor), Animal Diversity Web Staff.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
uses sound to communicate
living in landscapes dominated by human agriculture.
reproduction that is not sexual; that is, reproduction that does not include recombining the genotypes of two parents
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
an animal that mainly eats leaves.
An animal that eats mainly plants or parts of plants.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
fertilization takes place within the female's body
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
the area in which the animal is naturally found, the region in which it is endemic.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
breeding is confined to a particular season
remains in the same area
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.
uses sight to communicate
Anderson, R., E. Barnes, C. Bartlett. 1993. Restudy of Spirura infundibuliformis Mcleod, 1933 (Nematoda, Spiruroidea) from Spermophilus richardsonii, with observations on its development in insects. Canadian Journal of Zoology, 71/9: 1869-1873.
Coxwell, C., C. Bock. 1995. Spatial variation in diurnal surface temperatures and the distribution and abundance of an alpine grasshopper. Oecologia, 104/4: 433-439.
Ewen, A., M. Mukerji. 1979. Susceptibility of five species of Saskatchewan grasshoppers to field applications of Nosema locustae (Microsporida). The Canadian Entomologist, 111/8: 973-974.
Hadley, N., D. Massion. 1985. Oxygen-consumption, water-loss and cuticular lipids of high and low elevation populations of the grasshopper Orthoptera, Acrididae). Comparative Biochemistry and Physiology Part A- Physiology, 80/3: 307-311.(
Hamrick, K., J. Hamrick. 1989. Genetic-variation within and among populations of an alpine grasshopper, Journal of Heredity, 80/3: 186-192..
Maher, W. 1979. Nestling diets of prairie passerine birds at Matador, Saskatchewan, Canada. IBIS, 121/4: 437-452.
Otte, D. 1981. The North American Grasshoppers Vol. I. Cambridge, Massachussetts: Harvard University Press.
Pfadt, R. 2002. Field Guide to Common Western Grasshoppers. Laramie, Wyoming: University of Wyoming.