# Senegalese grasshopper

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Species of grasshopper

Senegalese grasshopper Senegalese grasshopper (OSE), Niger Scientific classification Kingdom: Animalia Phylum: Arthropoda Clade: Pancrustacea Class: Insecta Order: Orthoptera Suborder: Caelifera Family: Acrididae Subfamily: Oedipodinae Tribe: Locustini Genus: Oedaleus Species: O. senegalensis Binomial name Oedaleus senegalensis Krauss, 1877

The **Senegalese grasshopper** (*Oedaleus senegalensis*) is a medium-sized [grasshopper](/source/Grasshopper) [species](/source/Species) found in the [Sahel](/source/Sahel) region of [Africa](/source/Africa), the [Canary Islands](/source/Canary_Islands), [Cape Verde Islands](/source/Cape_Verde_Islands), and [West Asia](/source/West_Asia). Although not called a [locust](/source/Locust) in English, this species shows [gregarious behaviour](/source/Gregarious_behaviour) and some morphological change (phase [polymorphism](/source/Polymorphism_(biology))) on crowding.[1] 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](/source/Pearl_millet).[2]

## Description

### Adults

The basic colour of adult insects is a mixture of light beige and brown, but if they have grown up in green vegetation, a large proportion has varying degrees of green colouration, especially on the [head](/source/Head), [pronotum](/source/Pronotum), and [femora](/source/Arthropod_leg). The pronotum is [tectiform](/source/Tectiform), with an hour glass-shaped pattern on the [dorsum](/source/Dorsum_(anatomy)). The [wings](/source/Wing) extend clearly beyond the [abdomen](/source/Abdomen), the hind wings bearing a black, curved bar running from the front to the back with only a very slight interruption. This is the easiest character distinguishing this species from related ones found in the same distribution area. The bar of *[O. nigeriensis](https://en.wikipedia.org/w/index.php?title=Oedaleus_nigeriensis&action=edit&redlink=1)* has a large gap in the middle, while the one of *[O. johnstoni](https://en.wikipedia.org/w/index.php?title=Oedaleus_johnstoni&action=edit&redlink=1)* is only present on the posterior part of the wing.

### Nymphs

The colour of immature insects or [nymphs](/source/Nymph) is largely the same as that of the adults with green being predominant in green vegetation. Under crowded conditions, the nymphs develop increasingly extensive black markings. They can even form hopper bands like locusts, but these bands are not as cohesive as those of real locusts.

## Biology

This grasshopper is essentially [graminivore](/source/Graminivore). It consumes a fairly wide variety of [grasses](/source/Grass), but in the Sahel, it has a preference for cram-cram (*[Cenchrus biflorus](/source/Cenchrus_biflorus)*). It generally attacks cereals, especially [millet](/source/Millet) and [maize](/source/Maize). Adults like to eat the soft unripe grains. Grasses with a high [silica](/source/Silica) content are avoided.

This species generally has three generations per year during the rainy season, but evidence for the occasional fourth generation has been found during years of exceptionally longs rains. A number of adults of the first and second generations migrate north following the [Intertropical Convergence Zone](/source/Intertropical_Convergence_Zone). The adults of the third generation follow the zone on their way back to the south. At that time, populations have often greatly increased leading to the southward migration of huge numbers of grasshoppers, often at the time that millet is ripening in the fields. These can then cause serious damage to the crop. Though the aggregation of grasshoppers around points of light at night might give the impression of swarms, Senegalese grasshoppers do not, in fact, form cohesive swarms as locusts do.

[Eggs](/source/Egg_(biology)) are laid in sandy soil in small packets of about 20–40 eggs called [egg pods](https://en.wikipedia.org/w/index.php?title=Egg_pod&action=edit&redlink=1). Practically all eggs laid by the first and second generations hatch during the same season, usually within two weeks. However, most eggs of the third generation enter into [diapause](/source/Diapause) and survive the long dry season as a partly developed [embryo](/source/Embryo). Within two weeks of the first substantive rain (≥10 mm), about 60% of the eggs hatch, with the remaining 40% hatching after subsequent showers. This is an obvious adaptation to the erratic rains in the Sahel. In some years, the first hoppers that emerge perish because of lack of subsequent rain.

## Outbreaks and control

Outbreaks are frequent in Sahelian countries such as [Senegal](/source/Senegal), [Mauritania](/source/Mauritania), [Burkina Faso](/source/Burkina_Faso), [Mali](/source/Mali), [Niger](/source/Niger), and northern [Nigeria](/source/Nigeria), especially during wet years following several dry ones.

As with many locust species, outbreaks may be controlled with [insecticide](/source/Insecticide) spray operations: usually at [ULV](/source/Ultra-low_volume) rates of application and often via government or donor-aid sponsorship. A [biological pesticide](/source/Biological_pesticide) product called 'Green Muscle', which is based on an [entomopathogenic fungus](/source/Entomopathogenic_fungus) (*[Metarhizium acridum](/source/Metarhizium_acridum)*), is now available (see [desert locust](/source/Desert_locust)). Large-scale field tests on *O. senegalensis*, by the [LUBILOSA](/source/LUBILOSA) Programme in 1995-97, were amongst the first successful large-scale field tests using *Metarhizium* against acridoid pests.

## Gallery

		- Brown colour phase

		- Third instar female

		- Fourth instar male

		- Green fifth instar

		- Brown fifth instar

## References

1. **[^](#cite_ref-1)** Uvarov, B.P. (1966). "Phase polymorphism". *Grasshoppers and Locusts (Vol. 1)*. Cambridge University Press.

1. **[^](#cite_ref-2)** Maiga, I. H., M. Lecoq, and C. Kooyman. 2008. Ecology and management of the Senegalese grasshopper, Oedaleus senegalensis (Krauss 1877) (Orthoptera: Acrididae) in West Africa: review and prospects. Annales Societe Entomologique de France 44: 271–288.

## External links

- [AcridAfrica](http://acrida.info/)

- [Names in Dogon languages, with images from Mali](https://tsammalex.clld.org/parameters/oedaleussenegalensis)

Taxon identifiers Oedaleus senegalensis Wikidata: Q3349420 Wikispecies: Oedaleus senegalensis BioLib: 273394 BOLD: 804580 CoL: 48VCZ EoL: 494382 EPPO: ODALSG EUNIS: 256030 Fauna Europaea: 402374 Fauna Europaea (new): d0f124d0-1df0-4e2c-beb9-a21da7c2f196 GBIF: 1714146 iNaturalist: 480289 IRMNG: 10873666 NCBI: 1164880 Observation.org: 106284 Open Tree of Life: 712508 Orthoptera Species File (old): 1103210 Orthoptera Species File (new): 809879 Xeno-canto: Oedaleus-senegalensis

Authority control databases: National United States Israel

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Adapted from the Wikipedia article [Senegalese grasshopper](https://en.wikipedia.org/wiki/Senegalese_grasshopper) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Senegalese_grasshopper?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.