''Metarhizium acridum'' is the new name given to a group of fungal

isolates {{About, , the linguistics term dealing with languages unrelated to any other language in the world, Language isolate, other uses, Isolate (disambiguation){{!Isolate Isolates is a term used in developmental psychology and family studies, to describ ...

that are known to be virulent and specific to the

Acrididea Acrididea including the Acridomorpha is an infraorder of insects that describe the grasshoppers (thus also locusts) and ground-hoppers. It contains a large majority of species in the suborder Caelifera and the taxon Acridomorpha may also be use ...

(grasshoppers). Previously, this

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

has had

variety Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

status in ''

Metarhizium anisopliae ''Metarhizium robertsii'' formerly known as ''M. anisopliae'', and even earlier as ''Entomophthora anisopliae'' (basionym) is a fungus that grows naturally in soils throughout the world and causes disease in various insects by acting as a paras ...

'' (var. ''acridum'' ); before that, reference had been made to '' M. flavoviride'' or ''Metarhizium sp.'' describing an "apparently homologous and distinctive group" of isolates that were most

virulent Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to ...

against ''

Schistocerca gregaria The desert locust (''Schistocerca gregaria'') 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 sou ...

'' (desert locust) in early screening

bioassay A bioassay is an analytical method to determine the concentration or potency of a substance by its effect on living animals or plants (''in vivo''), or on living cells or tissues(''in vitro''). A bioassay can be either quantal or quantitative, dir ...

Biology

''M. acridum'' almost exclusively infects grasshoppers in the order Orthoptera. ''M. acridum'' infects only grasshoppers and locusts. Researchers believe that this has to do with the ''Mest1'' gene which is not present in ''M. acridum''. By taking a strain of '' M. robertsii'' that has a nonfunctioning ''Mest1 gene'', researchers found that the mutant was only able to infect ''

Melanoplus femurrubrum ''Melanoplus femurrubrum'', the red-legged grasshopper, is a species of grasshopper belonging to the genus '' Melanoplus''. It is one of the most common grasshoppers found in Mexico, the United States, and Canada. This grasshopper is frequently u ...

'', which is consistent with ''M. acridum'' activity. This allows the initiation of the infection process on the specific targets. The expression of '' Mest1'' in the entomopathogen ''M. acridum'' is triggered by substances that are only found on the waxy coat of the grasshoppers, which explains why this pathogen specifically only targets grasshoppers and locusts.

Applications

Pesticide

It has been used to control locusts. The international

LUBILOSA LUBILOSA was the name of a research programme that aimed at developing a biological alternative to the chemical control of locusts. This name is an acronym of the French title of the programme: Lutte Biologique contre les Locustes et les Sauteri ...

programme (which developed the product Green Muscle) identified and addressed key technical challenges for exploitation of microbial control agents, including isolate selection, mass production, and delivery systems ( formulation and application). Insect control (mortality) depends on factors such as the number of spores applied against the insect host, the formulation and weather conditions. Oil-based formulations allow the application of fungal spores under dry conditions, and are compatible with existing ultra-low volume (ULV) application techniques for locust control. As of 2012 ''M. acridum'' was under consideration by the USDA for release in the Western U.S. for control of native grasshoppers and crickets.

Important isolates

* IMI 330189 (= ARSEF 7486) is the ex-type of the species, originally collected from

Niger ) , official_languages = , languages_type = National languagesBenin Benin ( , ; french: Bénin , ff, Benen), officially the Republic of Benin (french: République du Bénin), and formerly Dahomey, is a country in West Africa. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the nort ...

: the active ingredient of 'NOVACRID'.

Gallery

Metarhizium acridum infecting locust (PLoS).jpg CSIRO ScienceImage 1367 Locusts attacked by the fungus Metarhizium.jpg, CSIRO isolate

References

{{Taxonbar, from=Q760265 Biopesticides Clavicipitaceae Parasitic fungi Fungi described in 2009