Critter Catalog

What do they look like?

Clubhorned grasshoppers are a medium-sized species compared to other grasshoppers. Females are longer than males, with females measuring 18 to 25 mm in length, and males measuring 16 to 20 mm long. They are gray or green in color with patterns and markings on them. The side of the face has a dark streak and a vertical white line. Their face is slanted, and the antennae have a dark club at the end, which gives these grasshoppers their name. Males have wings that are longer than their body, while females have much shorter wings.

Nymphs look like small versions of adults, but without wings and without the club on the antennae. The older nymphs have wing pads, which the younger nymphs do not. (Otte, 1981; Pfadt, 2002)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger
• sexes shaped differently

• Range length

  16 to 25 mm

  0.63 to 0.98 in

Where do they live?

Aeropedellus clavatus, the clubhorned grasshopper, is found throughout western Canada and the United States. It is found as far north as Alaska, and is present in Canada from the west coast to Manitoba. In the United States, it is common throughout the mid-western states, north from Montana and the Dakotas, east to Wisconsin and Iowa, and south through Utah, Colorado, New Mexico, and Arizona. (Hamrick and Hamrick, 1989; Otte, 1981)

• Biogeographic Regions
• nearctic
  • native

What kind of habitat do they need?

Clubhorned grasshoppers are found in two different habitats. In the northern parts of their range, in Canada and the northwestern United States, they live in prairies, grassy fields, and pastures from about 1740 to 2600 m above sea level. In the southern parts of their range in United States, these grasshoppers are found in high mountain meadows and tundra habitats, at elevations from about 3350 to 4150 m. Populations of clubhorned grasshoppers are not found in elevations between these high mountain meadows and low prairies. Both prairie and alpine habitats usually have lots of grass or sedge plants, and that is what these grasshoppers eat. (Alexander and Hilliard Jr., 1964; Coxwell and Bock, 1995; Hadley and Massion, 1985; Hamrick and Hamrick, 1989; Otte, 1981; Pfadt, 2002)

• These animals are found in the following types of habitat
• temperate
• terrestrial

• Terrestrial Biomes
• tundra
• savanna or grassland
• mountains

• Other Habitat Features
• agricultural

• Range elevation

  1740 to 4150 m

  5708.66 to 13615.49 ft

How do they grow?

Clubhorned grasshoppers undergo incomplete metamorphosis. Their life stages are egg, nymph, and adult. Eggs are laid in the summer, and hatch after one winter (prairie habitats) or after two winters (mountain habitats). Eggs hatch early in the spring, often when there is still snow on the ground. In prairies, they hatch in May, and in the mountains, they hatch starting in June. Since they live in mountain areas where spring and summer are short seasons, their development is quick. As nymphs, they have four stages called instars. In between each instar, they shed their skin. After 4 to 6 weeks, they become adults. By developing quickly, adults are present when there is still plenty of grass to eat, before the weather gets too cold. (Alexander and Hilliard Jr., 1964; Coxwell and Bock, 1995; Otte, 1981; Pfadt, 2002)

• Development - Life Cycle
• metamorphosis
• diapause

How do they reproduce?

There is little information available on the mating habits of clubhorned grasshoppers. They can probably mate many times with different mates. To find female mates, males make a buzzing "song" by rubbing their leg against a vein in their wing. (Pfadt, 2002)

• Mating System
• polygynandrous (promiscuous)

Females lay their eggs around the roots of grasses. The eggs are tan in color, about 5 mm long, and are laid in egg pods. Each egg pod has 5 to 8 eggs in them. The pods are made up of a tan, hardened material, and are placed in the soil or among grass roots. Multiple egg pods may be laid together, usually during the late summer, from August to September. The eggs stay in the egg pod for 1 or 2 winters. After hatching, the grasshoppers are ready to mate in 4 to 6 weeks. (Coxwell and Bock, 1995; Hamrick and Hamrick, 1989; Pfadt, 2002)

• Key Reproductive Features
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• asexual
• fertilization
  • internal
• oviparous

• How often does reproduction occur?

  Aeropedellus clavatus can mate many times throughout its life.

• Breeding season

  Mating and oviposition take place in the late summer.

Females provide nutrients in the eggs for the offspring to grow and develop on. They also lay the eggs in egg pods, which provide protection. After the egg pods are safely in the ground or in clumps of grass, the females leave and do not provide any more care. Males leave right after mating and do not provide any parental care. (Pfadt, 2002)

• Parental Investment
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female

How long do they live?

Clubhorned grasshoppers live through fall and winter as eggs, then hatch in the spring and grow for about 6 weeks before they are mature adults. As adults they probably survive only a month or two. If they are not eaten by predators, the adult grasshoppers will die when winter arrives. Only the eggs can survive freezing temperatures. Their total lifespan probably varies between 9 and 14 months. However, a few eggs, especially eggs laid at high altitude, don't hatch for 2 or 3 winters, so their total lifespan can be much longer. (Coxwell and Bock, 1995; Pfadt, 2002)

• Range lifespan
  Status: wild

  3.5 (high) years

• Typical lifespan
  Status: wild

  9 to 14 months

How do they behave?

Clubhorned grasshoppers are active during the day. Females cannot fly, because they have short wings, but males often make short flights. In between flights, they crawl on the ground. Females are not as active as males, and can often be seen on the ground, not moving. Since they cannot control their own body temperature, they have to sit in the sun to warm themselves up. They are also more active when it is sunny out, and less active when its rainy or cloudy. In the prairies of Canada, there can be many clubhorned grasshoppers in one area, up to 20 grasshoppers per square yard. In most other areas, there is only 1 to 4 grasshoppers per square yard. Males of this species may have a territory that they defend. (Coxwell and Bock, 1995; Hamrick and Hamrick, 1989; Pfadt, 2002)

• Key Behaviors
• flies
• diurnal
• motile
• sedentary
• solitary

Home Range

Clubhorned grasshoppers usually stay in the same general area of where they hatched. (Pfadt, 2002)

How do they communicate with each other?

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)

• Communication Channels
• acoustic

• Perception Channels
• visual
• tactile
• chemical

What do they eat?

Clubhorned grasshoppers are herbivores, and feed mainly on grasses. They have been recorded feeding upon 28 species of grass, and 6 species of sedge. They may also eat flowers, fungi, pollen, and occasionally other insects. (Alexander and Hilliard Jr., 1964; Otte, 1981; Pfadt, 2002)

• Primary Diet
• herbivore
  • folivore

• Animal Foods
• insects

• Plant Foods
• leaves
• pollen
• flowers

• Other Foods
• fungus

What eats them and how do they avoid being eaten?

Predators of clubhorned grasshoppers include birds, rodents, spiders, and carnivorous insects such as ants. Prairie birds are significant predators, such as the Horned Lark, Western Meadowlark, Chestnut-collard longspur, Sprague's Pipit, and White-Tailed Ptarmigan. The gray and green colors of these grasshoppers can act as camouflage, but since they live in mountain areas where there are not many plants besides grass, there are not many places to hide. To escape from predators, clubhorned grasshoppers hop away. (Coxwell and Bock, 1995; Kevan, et al., 1983; Maher, 1979; Pfadt, 2002)

• These animal colors help protect them
• cryptic

• Known Predators

  • birds, Aves
  • Horned Lark, Eremophila alpestris
  • Western Meadowlark, Sturnella neglecta
  • Chestnut-collard longspur, Calcarius ornatus
  • Sprague's Pipit, Anthus spragueii
  • White-Tailed Ptarmigan, Lagopus leucura
  • rodents, Rodentia
  • spiders, Araneae
  • insects, Insecta
  • ants, Formicidae

What roles do they have in the ecosystem?

Clubhorned grasshoppers are prey for birds, rodents, spiders, and other insects. They can also damage grasses by eating too much of them. They can be infected by the parasitic worm, Spirura infindibuliformis, and can also be infected by the protozoan Nosema locustae, which can cause death. (Anderson, et al., 1993; Ewen and Mukerji, 1979; Pfadt, 2002)

Do they cause problems?

Clubhorned grasshoppers can damage plants, since they eat grasses in prairies, meadows, and pastures. They also can eat wheat, and cause damage to wheat crops. In 1936 in Canada, a large number of clubhorned grasshoppers destroyed 300 acres of wheat. (Ewen and Mukerji, 1979; Pfadt, 2002)

• Ways that these animals might be a problem for humans
• crop pest

How do they interact with us?

Clubhorned grasshoppers do not have any positive effects on humans.

Are they endangered?

Clubhorned grasshoppers are not an endangered species.

• IUCN Red List

  Not Evaluated

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Contributors

Angela Miner (author), Animal Diversity Web Staff, George Hammond (editor), Animal Diversity Web Staff.

References

Alexander, G., J. Hilliard Jr.. 1964. Life History of Aeropedellus clavatus (Orthoptera: Acrididae) in the Alpin Tundra of Colorado. Annals of the Entomological Society of America, 57/3: 310-317.

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 Aeropedellus clavatus (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, Aeropedellus clavatus. Journal of Heredity, 80/3: 186-192.

Kevan, P., J. Cant, D. Kevan. 1983. Predator avoidance posturing of grasshoppers (Orthoptera: Acrididae) from the Colorado alpine and plains. The Canadian Entomologist, 115/2: 115-122.

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.