Mormon cricket (Anabrus simplex)

From HopperWiki
Jump to navigation Jump to search

Mormon cricket (Anabrus simplex)
Mormon cricket
Distribution
Washington, Oregon, California, Nevada, Idaho, Montana, Colorado, Wyoming, Arizona, New Mexico, Kansas, Nebraska, South Dakota, North Dakota, British Columbia, Alberta, Saskatchewan, Manitoba
Taxonomy
Family:Tettigoniidae
Subfamily:Tettigoniinae
Genus:Anabrus
Additional resources
Full taxonomy at OSF


The Mormon cricket (Anabrus simplex) is a large, flightless species of shield-backed katydid residing in western North America. It primarily feeds on grasses and shrubs, but may also consume agricultural crops.[1] Despite lacking functional wings in all stages of development, the Mormon cricket is known to be highly mobile and may travel extensively throughout a single season.[2] High density migratory bands of Mormon crickets are an economically significant agricultural pest in its native range.[3]

Nomenclature

Anabrus simplex Haldeman 1852. For full nomenclature, see this taxon's page on Orthoptera Species File


Identification

The Mormon cricket is not a true cricket, but rather a shield-backed katydid. This species is rather large, with adults ranging from 3.9 to 4.9 cm in length. It possesses long antennae and a shiny body. Adult males possess a bifurcated and uniquely shaped cercus, while the cercus of a female remains small and cone-shaped. Young nymphs are black, while older nymphs and adults may range in color from brown to dark brown to black.[4] Unlike closely related katydid species, the Mormon cricket is a completely flightless, ground-dwelling insect, and may be distinguished from closer relatives by viewing this behavior.[5]

Identification
Instar Color Wings Body length[5]
1 Black with white markings behind head[4] 6 - 8.2 mm
2 Black with white markings behind head[4] 6.8 - 8.9 mm
3 Black or dark brown with white markings behind head[4] 10.6 - 13.3 mm
4 Tan, brown, green, or black[4] 12 - 14 mm
5 Tan, brown, green, or black[4] 16 - 19 mm
6 Tan, brown, green, or black[4] 17.5 - 22 mm
7 Tan, brown, green, or black[4] 27 - 32 mm
Female adult Green, gray, brown, dark red, or black[6] Vestigial[6] 41 - 49 mm
Male adult Green, gray, brown, dark red, or black[6] Short, flightless, used for calling[6] 39 - 43 mm

Identification resources

Name Year published Resource link Descriptive keyword Language Geographic purview Author Year published
Field crop and forage pests and their natural enemies in Western Canada 2018 View URL Agriculturist guide, Education, Infographic, Management, Species identification, Integrated pest management English Canada Agriculture and Agri-Food Canada 2018
Field Guide to Common Western Grasshoppers 2002 View URL Species identification English United States of America United States Department of Agriculture 2002
Grasshopper Identification and Control Methods to Protect Crops and the Environment 2010 View URL Management, Species identification English Canada Agriculture and Agri-Food Canada 2010
Orthoptera Species File View URL Species identification, Biology English Africa, Americas, Asia, Europe, Oceania Orthoptera Species File Online
USDA ARS grasshopper species fact sheets View URL Management, Species identification English United States of America Agricultural Research Services, United States Department of Agriculture



Distribution

Mormon crickets reside exclusively in western North America. Populations may be found in rangeland habitat in both the United States and Canada. Its range includes the states of Idaho, Utah, Nevada, Oregon, Washington, Wyoming, Colorado, North Dakota, South Dakota, California, Arizona, Kansas, and New Mexico, as well as the Canadian provinces of British Columbia, Alberta, Saskatchewan, and Manitoba. Large populations concentrate in the Great Basin region and some western mountain ranges, including the Rocky Mountains. [4]

For more information and distribution records see [GBIF]

Biology

Habitat and ecology

Several Mormon crickets (Anabrus simplex) resting on a rock.

These insects prefer a heterogenous mountain or rangeland habitat, primarily dominated by sagebrush and forb plants.[7] They may also be found in mixed grasslands, shortgrass grasslands, and both broadleaf and coniferous forests.[2] A Mormon cricket’s diet may include, among seeds, fungi, and other arthropods, an incredibly wide variety of plant species. Nymphs and adults both display a preference for succulent forbs, and the species considers milkvetches, penstemon, arrowleaf balsamroot, dandelion, and wild mustards to be favorites. They may additionally feed on sagebrush and saltbush, found abundantly within their preferred range.[1] A variety of species prey on Mormon crickets, such as birds, rodents, wasps, and a small collection of parasitic organisms.[2] Of these, birds historically exert the most natural control over cricket populations.[7] Migrating Mormon crickets may also provide a significant prereproductive food source for native and nonnative stream fishes in some states, including a handful of endangered species.[8]

Mormon crickets are a flightless, yet extremely mobile species.[5] Young nymphs, those in the first four instars, undertake only short migrations in search of food. In contrast, older nymphs and adults may gather in massive migratory bands and travel 25 to 50 miles throughout a single season. This migration does not occur every season; in years of low cricket density, adults remain relatively solitary and may only travel short distances to favorable reproductive habitat. High density periods will lead to migratory bands and cricket outbreaks, and these periods may persist for five to twenty one years. The processes which control whether there will be a high or low density cricket year are uncertain, though predation (by birds) and harsh weather in early nymph stages may be important factors.[9] Swarming behavior may have formed as an evolutionary response to predation, as traveling in a band reduces the risk that an individual cricket will be eaten.[10] There is one generation of Mormon crickets annually in most regions. In high elevation populations, there may instead be a generation of crickets every other year. Females lay their eggs in summer, and the embryos finish development by fall, yet cold winter temperatures prompt the young to enter diapause and wait to hatch until the winter season is over. Mormon crickets hatch and emerge when the soil temperatures reach 40 degrees Fahrenheit (or 4.4 degrees celsius). This is a low temperature compared to other Orthoptera species. Young nymphs survive colder temperatures by sheltering within shrub canopies, between soil cracks, or beneath dry livestock dung. Nymphs and adults both exhibit basking behavior at sunrise and sunset as well, which aids in thermoregulation.[2] This insect has seven instars, and it takes approximately 60 to 90 days for a hatchling to reach adulthood in late spring. Ten to fourteen days later, males attempt to attract mates by means of song. During mating, the male transfers a spermatophore to the female, which she will partially absorb. The remainder of the structure will be eaten by the female, and the protein she acquires is essential for egg development.[11] This protein source serves as an unusually high contribution to the growth and survival of offspring among male insects.[12] A gravid female may occasionally lay eggs in cultivated fields, but she prefers sunny patches of bare ground which are east, south, or west facing.

Cannibalism occurs at a very high incidence in Mormon cricket populations. Food scarcity does not appear to be a necessary precursor or predictor of cannibalistic feeding, and there is no discrimination between sexes.[7] Risk of being cannibalized by other migrating individuals may incentivize a cricket to align properly during daytime movement and keep the migratory band cohesive.[13]

Land-use change

Mormon cricket reproductive success, and therefore density, is highly dependent on temperature. Increasing temperatures from climate change may cause the population of Mormon crickets in the United States and Canada to swell or crash in the future.[14]

Pest Status

A farmer with his flax crop, damaged by Mormon crickets.

The Mormon cricket was first noted as an agricultural pest by Mormon settlers in the Great Salt Lake Basin in 1848. As with many early outbreaks, there are no definite records of crop damage, yet anecdotes describe contact with migratory bands as having decimated crop fields before being brought under control by gull predation. The insect is named after this first recorded outbreak.[7]

Another significant outbreak occurred during a 17 year period between 1931 and 1948. At its peak in 1938, 19 million acres of crops across 11 states were affected. Damage in Montana and Wyoming alone in 1937 is estimated to have cost around $883,000.[5] Nevada, Idaho, and Oregon suffered significant losses during this outbreak, and Mormon cricket populations in these areas vastly outnumbered other grasshopper pests. Much of the information on this species’ ecology was collected in field studies as a portion of government control efforts in response to this outbreak.[3]

Migrating nymph and adult Mormon crickets are economically significant to the current day. Individuals may only remain in a field for three to four days, and can cause damage ranging from barely measurable to noticeably severe, depending on density.[5] Crickets primarily target wheat,[3] but may also attack alfalfa, barley, sugarbeets, sweetclover, small grains, and garden vegetables.[5] There may also be damages to livestock from migrating crickets feeding on grasses, but approximating the extent of this would be challenging at best. Mechanical barriers may prove ineffective as a means of control, as migrating bands will attempt to climb over artificial structures rather than altering the migration path to avoid them.[7] At the request of government agencies or private parties, the United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) may provide chemical control or insecticides to treat infested rangelands.[15]

Recent outbreaks

The most recent major outbreak of Mormon Crickets occurred in 2006, with 10 million acres in Nevada being affected by the insects. However, due to the migratory nature of Mormon cricket nymphs and adults, local minor outbreaks are common.[16] Some news and media organizations in Nevada have reported large bands of individuals moving through populated areas throughout the late spring and early summer of 2024.[17] Similar outbreaks previously occurred in the same areas a year prior.[18]

Outbreak media coverage

Name Year published Resource link Descriptive keyword Language Geographic purview Author Year published
Mormon cricket 'sludge' blankets northern Nevada roads causing crashes 2024 View URL Media article, Outbreaks English United States of America KLAS 8 News Now 2024



Associated organizations

Organization name Acronym Website Type Focus Focus keywords Geographic purview
National Grasshopper Management Board NGBM View URL Non-profit Organization Governance, Management Coordination, Natural sciences United States of America
USDA-APHIS-PPQ-Science & Technology-Insect Management and Molecular Diagnostics Laboratory (Phoenix Station) View URL Government Research, Management Management, Natural sciences United States of America


Resources

Name Year published Resource link Descriptive keyword Language Geographic purview Author Year published
Grasshopper Integrated Pest Management User Handbook 2000 View URL Biological control, Chemical control, Monitoring, Modeling, Population dynamics, Rangeland management, Decision making English United States of America Agricultural Research Services, United States Department of Agriculture 2000
Sustainable use and conservation of microbial and invertebrate biological control agents and microbial biostimulants 2023 View URL Management, Biological control, Biopesticide English Africa, Americas, Asia, Europe, Oceania Centre for Agriculture and Bioscience International 2023



References

  1. 1.0 1.1 Ueckert DN, Hansen RM (1970) Seasonal Dry-Weight Composition in Diets of Mormon Crickets. Journal of Economic Entomology 63: 96–98.
  2. 2.0 2.1 2.2 2.3 Capinera JL, MacVean CM (1987) Ecology and management of Mormon cricket, Anabrus simplex Haldeman. In Integrated Pest Management on Rangeland - A Shortgrass Prairie Perspective. Boulder Colorado: Westview Press, Chapter 9.
  3. 3.0 3.1 3.2 Swain R (1948) Nature and Extent of Mormon Cricket Damage to Crop and Range Plants. United States Department of Agriculture. Technical Bulletin 866, 44pp.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Wakeland C (1959) Mormon Crickets in North America. United States Department of Agriculture. Technical Bulletin 1202, 77pp.
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Wyoming Agricultural Experiment Station Bulletin "Mormon Cricket" 912: 1-4. https://www.ars.usda.gov/ARSUserFiles/30320505/grasshopper/Extras/PDFs/Species%20Fact%20Sheets/MormonCr.pdf
  6. 6.0 6.1 6.2 6.3 Neal SR (2009) The Evolution of Phenotypic Variation in Anabrus simplex (Orthoptera: Tettigoniidae): Shape Differences in Morphology and Patterns of Morphological Integration in Mormon crickets. Kent State University Available from: https://etd.ohiolink.edu/acprod/odb_etd/etd/r/1501/10?clear=10&p10_accession_num=kent1248095035 (June 13, 2024).
  7. 7.0 7.1 7.2 7.3 7.4 Cowan FT (1929) Life History, Habits, and Control of the Mormon Cricket. United States Department of Agriculture. Technical Bulletin 161, 28pp.
  8. Tyus HM, Minckley WL (1988) Migrating Mormon Crickets, Anabrus simplex (Orthoptera: Tettigoniidae), as Food for Stream Fishes. The Great Basin Naturalist 48: 25–30.
  9. Redak RA, Capinera JL, Bonham CD (1992) Effects of Sagebrush Removal and Herbivory by Mormon Crickets (Orthoptera: Tettigoniidae) on Understory Plant Biomass and Cover. Environmental Entomology 21: 94–102.
  10. Sword GA, Lorch PD, Gwynne DT (2005) Migratory bands give crickets protection. Nature 433: 703–703. https://doi.org/10.1038/433703a
  11. Gwynne DT (1993) Food Quality Controls Sexual Selection in Mormon Crickets by Altering Male Mating Investment. Ecology 74: 1406–1413.
  12. Gwynne DT (1984) Sexual Selection and Sexual Differences in Mormon Crickets (orthoptera: Tettigoniidae, Anabrus Simplex). Evolution 38: 1011–1022. https://doi.org/10.1111/j.1558-5646.1984.tb00371.x
  13. Bazazi S, Ioannou CC, Simpson SJ, Sword GA, Torney CJ, Lorch PD, Couzin ID (2010) The Social Context of Cannibalism in Migratory Bands of the Mormon Cricket. Marshall JAR (Ed.). PLoS ONE 5: e15118. https://doi.org/10.1371/journal.pone.0015118
  14. Srygley RB (2014) Effects of temperature and moisture on Mormon cricket reproduction with implications for responses to climate change. Journal of Insect Physiology 65: 57–62. https://doi.org/10.1016/j.jinsphys.2014.05.005
  15. Animal and Plant Health Inspection Service (2021) Protecting U.S. Rangeland From Grasshoppers and Mormon Crickets. United States Department of Agriculture. https://www.aphis.usda.gov/sites/default/files/fs-grasshoppers-mormon-crickets.pdf
  16. Johnson W, Macknet D Identification and Management of Mormon Crickets. Extension | University of Nevada, Reno. Available from: https://extension.unr.edu/publication.aspx?PubID=2346 (June 13, 2024).
  17. Bleakley C (2024) Mormon cricket ‘sludge’ blankets northern Nevada roads causing crashes. KLAS 8 News Now. Available from: https://www.8newsnow.com/news/local-news/mormon-cricket-sludge-blankets-northern-nevada-roads-causing-crashes/ (June 13, 2024).
  18. Gilbert A, Bigler K (2024) Mormon cricket infestation has returned for spring. KUTV. Available from: https://kutv.com/news/local/mormon-cricket-infestation-has-returned-for-spring-elko-nevada-infestation-invasion-bug-bugs-sludge (June 13, 2024).