''Isaria fumosorosea'' is an

entomopathogenic fungus An entomopathogenic fungus is a fungus that can kill or seriously disable insects. Typical life cycle These fungi usually attach to the external body surface of insects in the form of microscopic spores (usually asexual, mitosporic spores also ...

, formerly known as ''

Paecilomyces ''Paecilomyces'' is a genus of fungi. A number of species in this genus are plant pathogens. Several of the entomopathogenic species, such as "'' Paecilomyces fumosoroseus''" have now been placed in the genus ''Isaria'': in the order Hypocreale ...

fumosoroseus''. It shows promise as a

biological pesticide A Biopesticide is a biological substance or organism that damages, kills, or repels organisms seens as pests. Biological pest management intervention involves predatory, parasitic, or chemical relationships. They are obtained from organisms inclu ...

with an extensive host range.Dr Rajan Laboratories
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Life cycle

When a

conidium A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to th ...

blastospore A blastospore is an asexual fungal spore produced by budding. Produced by fungi within the phylum Glomeromycota and others. It is also known as a blastoconidium (plural = blastoconidia). An example of a fungus that forms blastospores is ''Candi ...

of ''Isaria fumosorosea'' lands on a suitable host, it produces enzymes to penetrate the insect's

cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...

. A germ tube then grows into the

haemocoel The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...

and the fungus proliferates inside the insect’s body. The fungus can also enter through the

spiracle Spiracle or spiraculum may refer to: * Spiracle (arthropods), opening in the exoskeletons of some arthropods * Spiracle (vertebrates), openings on the surface of some vertebrates * Spiraculum, a genus of land snails in family Cyclophoridae Cycl ...

s, the

mouth In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...

or the anal opening. The

mycelia Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates in ...

spread in the

haemolymph Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod (invertebrate) body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which ...

and tissues, eventually emerging from the insect and producing

conidia A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...

. Mortality of the insect has been ascribed to the drainage of its nutrients, the destruction of its tissues and the release of toxins.

Host range

This fungus has a wide host range that includes insects in over twenty five different families and many species of mite. Agricultural pest insects which are susceptible to infection include the

diamondback moth The diamondback moth (''Plutella xylostella''), sometimes called the cabbage moth, is a moth species of the family Plutellidae and genus '' Plutella''. The small, grayish-brown moth sometimes has a cream-colored band that forms a diamond along ...

(''Plutella xyllostella''), the

Russian wheat aphid The Russian wheat aphid (''Diuraphis noxia'') is an aphid that can cause significant losses in cereal crops. The species was introduced to the United States in 1986 and is considered an invasive species there. This aphid is pale green and up to 2 ...

(''Diuraphis noxia'') and the

silverleaf whitefly The silverleaf whitefly (''Bemisia tabaci'', also informally referred to as the sweet potato whitefly) is one of several species of whitefly that are currently important agricultural pests. A review in 2011 concluded that the silverleaf whitefly ...

(''Bemisia argentifolii''). Among mites, susceptible species include the spotted spider mite (''Tetranychus urticae''), the European red mite (''Panonychus ulmi''), the brown mite ('' Byrobia rubrioculus'') and the apple rust mite (''

Aculus schlectendali ''Aculus'' is a genus of mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genet ...

'').

Use in biological control

''Isaria fumosorosea'' has been used to control insect pests of plants grown for the production of

cut flowers Cut flowers are flowers or flower buds (often with some stem and leaf) that have been cut from the plant bearing it. It is usually removed from the plant for decorative use. Typical uses are in vase displays, wreaths and garlands. Many gardene ...

, ornamentals growing in greenhouses and nurseries, vegetable and cole crops, cotton, maize, rice and plantation crops. It has also been found to reduce the development and spread of powdery mildew, ''

Sphaerotheca fuliginea ''Podosphaera fuliginea'' (also known as ''Podosphaera xanthii'') is a plant pathogen that causes powdery mildew on cucurbits. ''Podosphaera fuliginea'' and '' Erysiphe cichoracearum'' are the two most commonly recorded fungi causing cucurbit pow ...

'', on cucumbers. A comparison made between several entomopathogenic

hyphomycetes Hyphomycetes are a form classification of fungi, part of what has often been referred to as fungi imperfecti, Deuteromycota, or anamorphic fungi. Hyphomycetes lack closed fruit bodies, and are often referred to as moulds (or molds). Most hyphom ...

showed that ''Isaria fumosorosea'' (as ''Paecilomyces fumosoroseus'') provided more effective control of the cabbage-heart caterpillar, ''

Crocidolomia binotalis ''Crocidolomia pavonana'' is a moth of the family Crambidae. Its caterpillar is a crop pest and is known as the croci or the cabbage cluster caterpillar. This moth is found in Africa and Asia, its range extending from South Africa through India ...

'', than did either ''

Beauveria bassiana ''Beauveria bassiana'' is a fungus that grows naturally in soils throughout the world and acts as a parasite on various arthropod species, causing white muscardine disease; it thus belongs to the entomopathogenic fungi. It is used as a biological ...

'' or ''

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 ...

''. Research at the USDA-ARS Bioactive Agents Research Unit in Peoria showed that blastospores start germinating at a faster rate on the cuticle of silverleaf whiteflies than do conidia. This suggests that the use of blastospores rather than conidia for the development of formulations would be advantageous. The fungus neither grows nor develops at temperatures above 32 °C and is not thought to be pathogenic to humans. It has not been found to be toxic to rats in laboratory experiments and is not considered to be harmful to birds, honey bees,Nengel, S. ''Preferal WG : Acute oral and contact toxicity to the honey bee, Apis mellifera L., in the laboratory.'' Biobest N.V. bumblebees or a wide range of non-target arthropods.

References

{{Taxonbar, from=Q10614986 Clavicipitaceae Biological pest control Insect diseases Fungi described in 1904 Biopesticides Parasitic fungi

Life cycle

Host range

Use in biological control

See also

References