Public Description of Metarhizium anisopliae (Metschn.) Sorokīn,

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Name: Metarhizium anisopliae (Metschn.) Sorokīn,
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 (Latest review: 2009-11-08 22:44:44 PST (-0800) by aporras)

Taxonomic Classification:

Kingdom: Fungi
Phylum: Ascomycota
Class: Sordariomycetes
Order: Hypocreales
Family: Clavicipitaceae
Genus: Metarhizium

General Description:

In lab, M. anisopliae has white mycelium. The hyphae are septate, branched, and has a hyaline, or “glass like” appearance. (
example of septate branching and hyaline appearance.
They reproduce asexually and have conidiophores that produce conidia. (
Example of Conidiospores
The conidiophores vary in length and usually grow in a branching fan or grouping pattern and looks similar to a tuft of hair. When looking at a specimen that is infected, it will appear to be a green color due to the colonies creating spores on the outside of the insect. ( The main thing to keep in mind that separates these fungi from other types of pathogenic fungi is that this species mainly infects insects. It is extremely rare to find cases of this fungi infecting anything but insects.

Diagnostic Description:

TABLE 1 Susceptibility testing of M. anisopliae by the NCCLS macrobroth<img alt=" " title=“\”\"">method
This link shows one of the main clincial differences between M. anisopliae and many other pathogenic fungi. Another clinical aspect that is worth mentioning is that it is able to infect immunocompetitent patients and immunocompromised patients as of late. This species can be distinguished most easily by the type of host specificity and germination triggers. These germination triggers are certain types of carbon sources found in the outer layer of the insect’s cuticle. This acts as the main food source for the hyphae to grow on and eventually mature and take over the insect resulting in its death. There are over two hundred types of insects that M. anisopliae can infect which include silk worms, grasshoppers, flies, beetles and ants along with many other species of insects. (Cloyd 1999)
Four seperate worms in four stages of M. anisopliae growth and reproduction.
M. anisopliae sporulating on a maggot
Diagnosis through microscopy and colony on Sabouraud dextrose agar shows that at first the colony is a white or cream color and then slowly turns brownish black from the center out as it grows. The colonies seem to reach between 4 and 7 cm in a 25 degree celcius incubator over 3 weeks and will have a smaller radius the higher the temperature goes. Also, the type of agar will also effect how efficient the colony grows. (


M. anisopliae has a very diverse distribution because of how many species there are on the planet. This means that wherever the fungi is, it has evolved to grow there. For example, if one went to a hot place, they might find M. Anisophliae that grows better at 37 degrees celcius while another species of M. Anisophliae is more apt to growing at 8 degrees celcius. This means that this fungus is global and can be found anywhere where there is soil and a host.


This Fungi has been found in forests, agriculture, high UV locations, and very damp areas. It can be on leaves, or the insect cadaver after the spores have matured and covered the surface. It usually deposits its spores in soil and then waits for another host to come in contact with the spores on the dead insect or where the insect had decomposed or died. This means that it usually lives in areas that are not heavily populated or with a lot of industrial areas.

Look Alikes:

Beauveria bassiana- type of fungi responsible for white muscardine disease in pest insects. It differs from M. anisopliae in the fact that it has a sexual and asexual form, but is similar in that this particular species name is for the asexual form just like M. anisopliae. (


Currently the spores are used as an insecticide by many countries not only for agriculture but medically as well. There is research being done by Imperial College and the University of Edinburgh in London currently that hopes to create a lethal type of M. anisopliae to kill mosquitoes to control the malaria problem. (McNeil 2005) Also, at the Indian Institute of Chemical Technology, a new industrial technique was discovered by using lipase in the production of bio-diesel, and unlike the previous technique it can be run at room tempurature. (


Cloyd, Raymond A. (1999). “The Entomopathogenic Fungus Metarhizium anisopliae”. Midwest Biological Control News VI (7).

McNeil, Donald G. Jr. (10 June 2005). “Fungus Fatal to Mosquito May Aid Global War on Malaria”. The New York Times 104: 135–151.


Entomophthora anisopliae was the old name, but this species has been renamed and subcatagorized into sections of the Metarhizium genus. The name that should be use for this specific species would be Metarhizium anisopliae var. anisopliae which is not to be confused with M. majus or M. acridum.

Description author: Ian M. Kopp (Request Authorship Credit)
Description editor: Andrea Porras-Alfaro

Created: 2009-10-29 22:45:28 PDT (-0700) by Ian M. Kopp (imkwiu5489)
Last modified: 2009-11-08 22:44:44 PST (-0800) by Andrea Porras-Alfaro (aporras)
Viewed: 2055 times, last viewed: 2015-11-28 03:13:22 PST (-0800)