Red locust

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Red locust
Nomadacris septemfasciata.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Orthoptera
Suborder: Caelifera
Family: Acrididae
Subfamily: Cyrtacanthacridinae
Tribe: Cyrtacanthacridini
Genus: Nomadacris
Uvarov, 1923 [1]
Species:
N. septemfasciata
Binomial name
Nomadacris septemfasciata
Nomadacris septemfasciata, verspreiding, gewysig van Bahana (1999) et al.png
  outbreak areas
  invasion areas
  isolated high concentrations

The red locust (Nomadacris septemfasciata) is a large grasshopper species found in sub-Saharan Africa. Its name refers to the colour of its hind wings. It is sometimes called the criquet nomade in French, due to its nomadic movements in the dry season. When it forms swarms, it is described as a locust.

Contents

Nomadacris septemfasciata is in the family Acrididae and is the only member of the genus Nomadacris. [2] The genus Nomadacris was erected in 1923 by Boris Uvarov and the species was named originally as Acridium septemfasciatum by Jean Guillaume Audinet-Serville in 1838. [1] [2] It is placed in the subfamily Cyrtacanthacridinae, the bird locusts. [2] Other species previously placed in Nomadacris are now considered part of the genus Patanga . [2]

Description

Adults

The overall colour of adult insects is a mixture of light beige and brown. They have seven brown transverse bands on the elytra, justifying the species name septemfasciata. The pronotum has two brown lateral bands.

Males are 60–70 mm (2.4–2.8 in) long; females are 60–85 mm (2.4–3.3 in) long.

Nymphs

Unlike adults, the colour of immature insects varies depending on their phase. When solitary, they can be green or brown; when in large numbers (gregarious), they are bright yellow and red-brown with black markings.

Ecology

Red locusts actively seek out moist environments such as seasonal floodplains. Grains are their primary food source, so grassy lowlands are prime habitat. They also like spending time in trees and thus prefer some tree cover.

Red locusts are sedentary when ample shelter, perches, and food are available. In dry years, when the amount of suitable habitat is reduced, population densities increase. If the population density increases past a threshold, the locusts transform into their gregarious phase, changing their behaviour and anatomy. When gregarious, red locusts keep together in large swarms and fly with the wind in daylight hours, looking for more food. The higher temperatures during daylight enable gregarious locusts to travel longer distances by flying longer and higher, aided by thermal lift. [3] A swarm rarely moves more than 20–30 km in a day. In contrast, solitary locusts prefer to fly in the dark and do so alone. [4]

Compared to their solitary phase, gregarious red locusts also have:

Swarming females often lay eggs at night. Their young immediately behave gregariously and are capable of "hopping" hundreds of metres every day.

Outbreaks

Outbreak areas have been identified in Zambia, Tanzania, Malawi, Madagascar, and Réunion. In the Sahel, the species is observed on a more incidental basis in Cape Verde, the central Niger River delta in Mali, and around Lake Chad. Large swarms attacked the KwaZulu-Natal region which contributed to creating conditions which favoured the 1890s African rinderpest outbreak. [5] The last widespread plague occurred from 1930 to 1944, when almost all of southern Africa was invaded.

Hoppers killed by the fungus Metarhizium acridum Red locust with Metarhizium.jpg
Hoppers killed by the fungus Metarhizium acridum

After unsuccessful efforts to control the locusts through environmental modifications, chemical agents are currently being used. A biological product based on an entomopathogenic fungus, Metarhizium acridum , is now available (see desert locust). It has been successfully tested on both nymphs and adults of the red locust. However, over recent years, a new mechanism to control pests was created. The Integrated pest management (IPM) is a combination of environmentally friendly methods that together can be used effectively as a pest management strategy. [6]

Related Research Articles

<span class="mw-page-title-main">Locust</span> Grasshopper that has a swarming phase

Locusts are various species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstances they become more abundant and change their behaviour and habits, becoming gregarious. No taxonomic distinction is made between locust and grasshopper species; the basis for the definition is whether a species forms swarms under intermittently suitable conditions; this has evolved independently in multiple lineages, comprising at least 18 genera in 5 different subfamilies.

<span class="mw-page-title-main">Rocky Mountain locust</span> Extinct species of grasshopper

The Rocky Mountain locust is an extinct species of grasshopper that ranged through the western half of the United States and some western portions of Canada with large numbers seen until the end of the 19th century. Sightings often placed their swarms in numbers far larger than any other locust species, with one famous sighting in 1875 estimated at 198,000 square miles (510,000 km2) in size, weighing 27.5 million tons and consisting of some 12.5 trillion insects, the greatest concentration of animals ever speculatively guessed, according to Guinness World Records.

<span class="mw-page-title-main">Desert locust</span> Species of grasshopper

The desert locust is a species of locust, a periodically swarming, short-horned grasshopper in the family Acrididae. They are found primarily in the deserts and dry areas of northern and eastern Africa, Arabia, and southwest Asia. During population surge years, they may extend north into parts of Southern Europe, south into Eastern Africa, and east in northern India. The desert locust shows periodic changes in its body form and can change in response to environmental conditions, over several generations, from a solitary, shorter-winged, highly fecund, non-migratory form to a gregarious, long-winged, and migratory phase in which they may travel long distances into new areas. In some years, they may thus form locust plagues, invading new areas, where they may consume all vegetation including crops, and at other times, they may live unnoticed in small numbers.

<span class="mw-page-title-main">Migratory locust</span> Species of grasshopper

The migratory locust is the most widespread locust species, and the only species in the genus Locusta. It occurs throughout Africa, Asia, Australia and New Zealand. It used to be common in Europe but has now become rare there. Because of the vast geographic area it occupies, which comprises many different ecological zones, numerous subspecies have been described. However, not all experts agree on the validity of some of these subspecies.

<span class="mw-page-title-main">Bandwing</span> Subfamily of grasshoppers

Bandwings, or band-winged grasshoppers, are the subfamily Oedipodinae of grasshoppers classified under the family Acrididae. They have a worldwide distribution and were originally elevated to full family status as the Oedipodidae. Many species primarily inhabit xeric weedy fields, and some are considered to be important locusts:

<span class="mw-page-title-main">Caelifera</span> Suborder of insects

The Caelifera are a suborder of orthopteran insects. They include the grasshoppers and grasshopper-like insects, as well as other superfamilies classified with them: the ground-hoppers (Tetrigoidea) and pygmy mole crickets (Tridactyloidea). The latter should not be confused with the mole crickets (Gryllotalpidae), which belong to the other Orthopteran sub-order Ensifera.

<span class="mw-page-title-main">Senegalese grasshopper</span> Species of grasshopper

The Senegalese grasshopper is a medium-sized grasshopper species found in the Sahel region of Africa, the Canary Islands, Cape Verde Islands, and West Asia. Although not called a locust in English, this species shows gregarious behaviour and some morphological change on crowding. In many parts of the Sahel, this species may cause greater year-on-year crop damage than better-known locusts, attacking crops such as the pearl millet.

<span class="mw-page-title-main">Brown locust</span> Species of grasshopper

The brown locust is a medium-sized small locust species in the monotypic genus Locustana. It is found in Southern Africa and shows classic gregarious behaviour with phase polymorphism on crowding.

<i>Hieroglyphus daganensis</i> Species of grasshopper

The African rice grasshopper, Hieroglyphus daganensis is a medium-sized grasshopper species found in the Sahel region. Although not called a locust in English, this species shows gregarious behaviour and some morphological change on crowding and may become a moderately important pest species for small-holder farmers in the region.

<i>Dociostaurus maroccanus</i> Species of grasshopper

Dociostaurus maroccanus, commonly known as the Moroccan locust, is a grasshopper in the insect family Acrididae. It is found in northern Africa, southern and eastern Europe and western Asia. It lives a solitary existence but in some years its numbers increase sharply, and it becomes gregarious and congregates to form swarms which can cause devastation in agricultural areas. The species was first described by Carl Peter Thunberg in 1815.

<i>Calliptamus italicus</i> Species of grasshopper

Calliptamus italicus, the Italian locust, is a species of 'short-horned grasshopper' belonging to the family Acrididae, subfamily Calliptaminae.

<i>Schistocerca americana</i> Species of grasshopper

Schistocerca americana is a species of grasshopper in the family Acrididae known commonly as the American grasshopper and American bird grasshopper. It is native to North America, where it occurs in the eastern United States, Mexico, and the Bahamas. Occasional, localized outbreaks of this grasshopper occur, and it is often referred to as a locust, though it lacks the true swarming form of its congener, the desert locust.

<i>Patanga succincta</i> Species of locust

Patanga succincta, the Bombay locust, is a species of locust found in India and southeast Asia. Usually a solitary insect, only in India has it has exhibited swarming behaviour. The last plague of this locust was in that country between 1901 and 1908 and there have not been any swarms since 1927. It is thought that the behaviour of the insects has altered because of changing practices in agricultural land use.

<i>Locusta migratoria manilensis</i> Subspecies of locust

Locusta migratoria manilensis, commonly known as the Oriental migratory locust, is a subspecies of the migratory locust in the family Acrididae. It is sufficiently different in size and structure from the African migratory locust to be considered a distinct subspecies of the migratory locust. It is found in southeastern Asia and is an important agricultural pest in the region. It is normally a solitary insect but when conditions are suitable, it enters into a gregarious phase when the young form into bands which move together and the adults into swarms. Although outbreaks may have recently been fewer in number and size because of changes in agricultural practices and better locust detection, the insects remain active as crop pests and the potential for outbreaks is still present.

<span class="mw-page-title-main">African migratory locust</span> Subspecies of locust

Locusta migratoria migratorioides, commonly known as the African migratory locust, is a subspecies of the migratory locust family Acrididae.

<i>Anacridium moestum</i> Species of grasshopper

Anacridium moestum, the camouflaged tree locust, is a species of grasshopper belonging to the family Acrididae, that is native to Africa south of the equator. It is similar in appearance to the Southern African desert locust, Schistocerca gregaria flavicentris. It is likewise brownish, large and slender, but mostly arboreal in its habits.

<span class="mw-page-title-main">Cyrtacanthacridinae</span> Subfamily of grasshoppers

The Cyrtacanthacridinae are a subfamily of Orthoptera: Caelifera in the family Acrididae. They are sometimes referred-to as bird locusts, criquets voyageurs in French-speaking Africa, and Knarrschrecken in German.

<i>Patanga</i> (grasshopper) Genus of grasshoppers

Patanga is a genus of grasshoppers in the subfamily Cyrtacanthacridinae. Species are distributed throughout Asia: from India, China, Japan, Indochina and western Malesia. The genus was named by Boris Uvarov in 1923, with the type species the economically significant Bombay locust, which has also been placed in genus Nomadacris.

<i>Calliptamus</i> Genus of grasshoppers

Calliptamus is a genus of grasshoppers in the family Acrididae. Species of Calliptamus are found in Africa and the northern Palearctic realm through to Japan.

References

  1. 1 2 Uvarov BP (1923) "A revision of the Old World Cyrtacanthacrini (Orthoptera, Acrididae) – I. Introduction and key to genera." Annals and Magazine of Natural History (9) vol. 11 143
  2. 1 2 3 4 Cigliano, M. M.; Braun, H.; Eades, D. C.; Otte, D. "genus Nomadacris Uvarov, 1923". orthoptera.speciesfile.org. Orthoptera Species File. Retrieved 30 December 2018.
  3. Farrow, R.A. "Flight and Migration in Acridoids". Biology of Grasshoppers. John Wiley and Sons.
  4. Chapman, R.F. (1959). "Observations On the Flight Activity of the Red Locust, Nomadacris Septemfasciata (Serville)". Behaviour. 14 (1): 300–334. doi:10.1163/156853959X00126.
  5. Ballard, Charles (1986). "The Repercussions of Rinderpest: Cattle Plague and Peasant Decline in Colonial Natal". The International Journal of African Historical Studies. 19 (3): 421–450. doi:10.2307/218974. ISSN   0361-7882. JSTOR   218974.
  6. Andiatsirevombola et al., 2016