biology

Metarhizium brunneum

Metarhizium brunneum is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Metarhizium brunneum rather than just read about it. In short: Metarhizium brunneum is the re-instated name of a group of reassigned Metarhizium isolates, previously grouped in the species "Metarhizium anisopliae var. anisopliae": based on a multigene phylogenetic approach using near-complete sequences from nuclear DNA. It is a mitosporic fungus with asexual reproduction, which was formerly classified in the form class Hyphomycetes of the form phylum Deuteromycota (also often c…

Key takeaways

Metarhizium brunneum belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Metarhizium brunneum to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Metarhizium brunneum from memory before moving on to harder problems.

Reference excerpt

Metarhizium brunneum is the re-instated name of a group of reassigned Metarhizium isolates, previously grouped in the species "Metarhizium anisopliae var. anisopliae": based on a multigene phylogenetic approach using near-complete sequences from nuclear DNA. It is a mitosporic fungus with asexual reproduction, which was formerly classified in the form class Hyphomycetes of the form phylum Deuteromycota (also often called Fungi Imperfecti). M. brunneum has been isolated from Coleoptera, Lepidoptera, Diptera and soil samples, but a commercially developed isolate (below) has proved virulent against Hemiptera and Thysanoptera.

Taxonomy Within the M. anisopliae species complex, there is a tight cluster of species which is informally referred to as the “PARB clade”, based on the specific epithets of the four species originally included in the group (M. pinghaense, M. anisopliae, M. robertsii and M. brunneum). Metarhizium brunneum is sister to the remaining lineages within the clade.

Genome The genome of M. brunneum was the first in the genus to be completely assembled. The 7 chromosomes and mitogenome have a total sequence length of 37,796,881. The sequencing and assembly was performed at Swansea University in 2021.

Standard isolate and characteristics Bischoff et al.[1] state: "There is no viable ex-type culture for M. brunneum Petch. However ARSEF 2107 (from Oregon, USA) is considered an authentic strain because the taxon's author, Petch, identified it and we designate it here as an ex-epitype. ... an ex-epitype (BPI 878297) derived from a living culture (ARSEF 1914) is designated for this taxon." It appears impossible to differentiate isolates of M. brunneum from M. anisopliae, on morphological characteristics alone (with the exception of the presumptive colour mutant ARSEF 2107). Conidia typically measure 4.5–8.0 μm long x 2.0–3.0 μm diameter: similar to several other Metarhizuim species. Petch designated a type collection from the Philippines, which he described as turning brown in mature colonies. This colour variant may occur regularly in nature based on the fact that Petch had identified a number of isolates as M. brunneum from geographically distant locations. However, the majority of M. brunneum isolates examined by Bischoff et al. were olive-green in colour (similar to M. anisopliae), rather than the buff and tan pigmentation described for the type specimen and the ex-epitype cultures, respectively.

Applications

Varroa mite (honeybees) In 2021, a custom-bred strain of M. brunneum was created to target and kill the varroa mite that afflicts honeybee populations. That strain was bred to be heat-tolerant, raising the percentage of spores that germinated at 35 °C—the temperature of a typical beehive— from 44% to 70%. A second breeding effort increased the deadliness of the strain from 4% just over 60%.

Important isolates Isolate M.a. 43 (a.k.a. F52, Met52, 029056) primarily infects beetle larvae: and is the active ingredient of 'BIO 1020', originally developed for control of Otiorhynchus sulcatus and now 'Met52'; it is still often described in commercial literature as "M. anisopliae". Commercial products based on this isolate are subcultures of the individual isolate M.a. 43 and are represented in several culture collections including: Julius Kühn-Institute for Biological Control (previously the BBA), Darmstadt, Germany: [M.a. 43]; HRI, UK: [275-86 (acronyms V275 or KVL 275)]; KVL Denmark [KVL 99-112 (Ma 275 or V 275)]; Bayer, Germany [DSM 3884]; ATCC, USA [ATCC 90448]; USDA, Ithaca, USA [ARSEF 1095]. Granular and emulsifiable concentrate formulations based on this isolate have been developed by several companies and registered in the EU and N. America (US and Canada) for use against black vine weevil in nursery ornamentals and soft fruit, other Coleoptera, western flower thrips in greenhouse ornamentals and chinch bugs in turf.

Worked examples

Example 1 — a first encounter with Metarhizium brunneum

Start with the simplest possible case. Write down what Metarhizium brunneum claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Metarhizium brunneum before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Metarhizium brunneum ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Metarhizium brunneum

In research: Metarhizium brunneum appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Metarhizium brunneum in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Metarhizium brunneum is common in secondary-school and first-year university syllabi. It links to neighbouring topics Clavicipitaceae, Fungi described in 1935, Fungus species, so understanding it makes those chapters shorter.
In everyday life: Look for Metarhizium brunneum outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Metarhizium brunneum in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Metarhizium brunneum means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Metarhizium brunneum out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Metarhizium brunneum in simple terms?

Why does Metarhizium brunneum matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Metarhizium brunneum?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Metarhizium brunneum.