Fungus Facts

There are over 100,000 different fungi recorded in taxonomy. However some experts say there may actually be over one million. The majority of these unrecorded species are hidden in the deeper reaches of tropical rainforest. There you will find billions, yet to be discovered Bacteria, Archaea, Algae, Protozoa and all of the larger plants and animals. Fungi are under appreciated by most gardeners, when in actuality they play the major role in the soil food chain web as the major decay agent. Nutrients are released as waste byproducts after they are eaten or when the fungi die and decay themselves. Soil fungi form a very important symbiosis with plants. More than 90% of all plants form a beneficial relationship with mycrrhizae fungi. These relationships evolved when life was beginning here on Earth some 450,000,000 years ago. These fungal partners extend the reach and the surface area of plant roots. Tree roots, for example, can extend their feeding area an incredible 700 times by a fungal relationship.

Hirsutellia Biocontrol Fungus

Hirsutellia Biocontrol Fungus

Hirsutella is a genus of asexually reproducing fungi in the Ophiocordycipitaceae family, which contain about 65 species (Hodge 1998). It is a moniliaceous, entomopathogenic fungal pathogen, which produces an insecticidal protein named hirsutellin. Hirsutellin has been described to be toxic against a wide rage of small insects including larvae, aphids, mites and nematodes. Hirsutella was originally described by French mycologist Narcisse Théophile Patouillard in 1892, creating interest in the use of these fungi as biological controls of insect pests. The teleomorphs of Hirsutella species belong to the genera Ophiocordyceps and Torrubiella. Hirsutella is a Hyphomycetes, a form-class of Fungi, part of what has often been referred to as Fungi imperfecti, Deuteromycota, or anamorphic fungi. Hyphomycetes lack closed fruiting bodies, and are often referred to as molds. They have unusual phialides that taper into a long narrow neck, and produce usually only 1–3 conidia in a dense terminal sphere of slime. Most Important Hursutella Species The genus Hursutella contain approximately 30 species. By no means all of these species are viable bio-control agents. The most important bio-control agents are Hirsutella verticillioides, Hirsutella thompsonii, Hirsutella citriformis and Hirsutella rhossiliensis. Rhossiliensis being very effective against nematodes. If you are up on your Spanish you might be interested in the report FAO Hirsutella put together jointly between the Instituto de Investigaciones and the Centro de Investigaciones Agropecuarias (CIAP), Universidad Central de Las Villas, Cuba. Hirsutellia Mode of Action Hirsutellia controls the growth of certain harmful bacteria and fungi, presumably by competing for nutrients, growth sites on plants, and by directly colonizing and attaching to fungal pathogens. A detailed description of the mode of action can be gleaned from the Journal of Invertebrate Pathology Entitled “The Mode of Action of Hirsutellin A on Eukaryotic Cells” In summary, Hirsutella has been found to be the first mycotoxin of a invertebrate mycopathogen determined to possess ribosomal inhibiting activity and appears to possess some specificity to invertebrate cells. Research Related to Biocontrol Agent Hirsutellia Toxicity of Hirsutella Against Mites– INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY Toxicity of Hirsutella Against Mites- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense Hirsutellin A, a toxic protein produced in vitro by Hirsutella thompsonii– Station de Recherches de Pathologie Comparee INRACNRS, Saint-Christol- Lez-Ales,...

Read More

Fungus Isaria fumosorosea Controls Flys

Fungus Isaria fumosorosea Controls Flys

 Fungus Isaria fumosorosea General Information Isaria fumosorosea, was first described as Paecilomyces fumosoroseus by M. Wize in 1904. It is now considered a very effective fungal entomopathogen. It was discovered by M. Wize in a suffering sugar beet weevil in the Ukraine but has a huge distribution range. Isaria fumosorosea is a species complex rather than a single species. This means there are wide variations. Undoubtedly there will be taxonomic revisions of this group in the future (Zimmermann, 2008). Isaria fumosorosea is found in the soil, on plants, in the air, on every continent in the world except Antartica (Cantone and Vandenberg, 1998), (Zimmerman, 2008)  It has been found to effect over forty species of arthropods. Susceptible organisms include some of the more problematical horticultural pests. A few mentionables being, whiteflies, thrips, aphids and termites. (Smith, 1993; Dunlop et al. 2007; Hoy et al. 2010) Because of its wide range of arthropodial host, it has received significant attention in research as a biological control agent. Much of the research has been focused on controlling the whitefly, Bemisia tabaci. We have an interesting post describing the use of Isaria in combination with  Lecanicillium and Paecilomyces lilacinus. We have found it quite effective. It is a product that will convince the traditional horticulturalist to think “microbe”.  Fungus Isaria fumosorosea Mode of Action Like most entomopathogenic fungi, Isaria fumosorosea, infects its host by dissolving the insects cuticle (Hajek and Leger, 1994). Various metabolites allow the Isaria fumosorosea to penetrate the host insect and inhibit its regulatory system. The active enzymes exuded by Isaria fumosorosea include proteases, chitinases, chitosanase, and lipase (Ali et al. 2010). These allow it to breach the arthopods cuticle and disperse through the hemocoel.  Isaria fumosorosea also produces beavericin (Luangsa-ard et al. 2009). Beavericin paralyzes the host cells (Hajek and Leger, 1994). Affectable arthropods exposed to blastospores and conidia show slowed growth and high counts of mortality (Dunlap et al. 2007).  Fungus Isaria fumosorosea Mode of Application Worldwide, it is currently used in 8 different mycoacaricides and mycoinsecticides (Faria and Wraight, 2007). All are considered safe and non-toxic to humans (Dalleau-Clouet et al. 2005)  Perhaps the most interesting aspect of its use is that it has little effect on most off target beneficial insects when used correctly (Zimmerman, 2008). Tests show that the fungus is not toxic to mammals nor birds as well as humans. Isaria fumosorosea can and should be applied in combination with other entomopathogenic fungus such as Lecanicillium and Beauvaeria. The diluted mix is sprayed not only on the upper and lower leaves, but over the entire phylosphere of the plant in the soft morning or evening light. Keep in mind there are several factors which influence the growth and stability of Isaria fumosorosea. These include temperature, relative humidity, radiation, and the host plant of the target insect (Zimmerman 2008). It works best at temperatures between 22⁰C and 30⁰C (72⁰F-86⁰F), and requires high humidity. Exposure to sunlight can have serious negative effects on survival of I. fumosorosea (Zimmerman 2008). Studies demonstrate that UV radiation, particularly wavelengths in the UV-A and UV-B(400 to 280 nm) region are the most problematical. Isaria fumosorosea was registered as an active ingredient in a Manufacturing Use Product and in one End-use Product for non-food use in greenhouses in October 1998 in the USA. These products are now labeled for non-food and for agricultural food uses. An exemption from tolerance was established in 40 CFR 180.1306 in September 2011.  References Ali, S., Huang, Z., and Ren, S. 2010. Production of cuticle degrading enzymes by Isaria fumosorosea and their evaluation as a biocontrol agent against diamondback...

Read More

Beauveria bassiana Entomopathogenic Fungi

Beauveria bassiana Entomopathogenic Fungi

Beauveria bassiana General Information Beauveria bassiana, formerly also known as Tritirachium shiotae, is an entomopathogenic fungus (parasitic to insects) that grows naturally in soils throughout the world.  It acts as a parasite on a very wide variety of arthropods, including, whiteflies, termites, thrips, aphids, beetles,caterpillars, weevils, grasshoppers, ants, mealybugs, bedbugs and even malaria-transmitting mosquitoes. Insects vary in susceptibility to different strains. Strains have been collected from different infected insects and cultured to create a particular product for commercial use. The product is made via a bio-fermentation process. The spores (conidia) are extracted and made into a sprayable form. Beauveria bassiana was named after the Italian entomologist Agostino Bassi. He first found B bassiana in 1835 as the cause of the muscardine disease of the domesticated silkworms. Supplemental Material Fact Sheet.pdf Beauveria bassiana Mode of Action Beauveria bassiana kills arthropods as a result of the insect coming into contact with the conidia (fungal spores). contact is made in several ways. The most common and effective is the spray droplets landing on the pest or by walking on a treated surface.  Once the fungal spores attach to the insect’s cuticle, the fungus spores germinate sending out threaded hyphae which penetrate the insect’s body and proliferate. It takes 3 to 5 days for an infected insects to die. The dead insect may serve as a source of spores for secondary spread of the fungus. An infected adult male will also transmit the fungus during mating. (Long et al. 2000). Click here to learn more The conidia of Beauveria. bassiana adhere to the insect cuticle by means of hydrophobic interaction between the spore wall and epicuticle lipids. The conidia germinate, and the germ tube penetrates the cuticle, using a specific series of enzymes, which in turn degrade the lipids, protein and chitin in the insect cuticle. In the insect body, the fungus multiplies in the haemocoel as a blastospore, or yeast-like cell, and enzymes begin to destroy the internal structures of the host insect causing morbidity within 36 – 72 hours. Reduced feeding and immobility are rapidly evident, The insect dies within between 4 to 10 days post-infection. The time to death will depend on the insect species, age and conidial dose. After death, the blastospores transform into mycelia, which emerge through the cuticle and form spores. These cover the cadaver as a characteristic white growth. Sporulation occurs only in conditions of high humidity. Beauveria bassiana Mode of Application The liquid spray should have a concentration of at least 2.5X109 viable spores. High humidity and water amplify the activity of the conidia and the infection. Fungal spores are readily killed by solar radiation. It is best to spray the plants with the anthropoid pests in the morning or late afternoon, in cool to moderate temperatures (Goettel et al. 2000, Wraight and Ramos 2002). Apply the Beauveria bassiana liquid spray to the top as well as the undersides of the leaves or wherever the arthropod primarily occurs. Good coverage is a must. The spores have a relatively short life cycle, so it is important that the spray has sufficient opportunity to contact the insect. For insects that bore into a plant, control is difficult. For best results, applications should be made during the early growth stages of the insect before much damage has occurred. Speed of kill depends on the number of spores contacting the insect, insect age, susceptibility and environmental conditions. Beauveria bassiana has a wide host range and should be considered a non-selective biological insecticide. These should not be applied to flowers visited by pollinating...

Read More

Endophytes Fungi & The Phyllosphere

Endophytes Fungi  & The Phyllosphere

A significant symbiotic partnership among fungi and plants is created by endophytes. Endophytic fungi, in contrast to their subterranean, root loving mycorrhizal fungus, have adjusted to exist in the upper components of plants. They reside in the stems, leave, and bark. Plant surfaces are taken over by countless endophytic fungal varieties. The main reason these types of microbes have escaped researchers awareness for so very long is that nearly all survive inside their host without any noticeable symptoms. Little by little the scientific community focused on the important role of endophytel fungus. Researchers have recognized endophytes importance since early 1900, however they attracted a lot more attention in the mid 1970s. This is when an assessment was made of livestock in various pastures and the grasses they were eating. Then, an analyze in the early ’80s with rye grass demonstrated exactly how endophytic fungus greatly improved the rye’s ability to resist insect damage. Afterwards research established that a few lawn grasses have an endophyte derived potential to deal with many other fungus. Endophytis fungus promises a new set of bioproducts to enhance plant growth, and health. This indicates many endophytic fungus display certain benefit to its host flowers and plants. As an example, several generate toxins which destroy aphids along with other pesky sucking bugs that assault the host. A few endophytes increase the host’s seedling germination, insuring group survival. Other Endophytic fungi generate antipathogenic compounds or stimulate the host herb to boost resistance to disorders. Several endophytic fungus begin the decomposition process as soon as the host plant dies. This ensures the recycling of nutrients, to the host plant’s. image credits: top, Fungal endophyte (Kaminskyj lab), right- Australia Pacific Science...

Read More

Mycorrhizal Fungus

Mycorrhizal Fungus

Mycorrhizal Fungus is one of the most researched fungi. It  has long been recognized as a very important component to plant health. It maintains a symbiotic relationship to more than 80% of all plants. With it’s extensive hyphae network of pseudo-roots, it increases plant water and nutrient uptake 10 to 1000 times. This is why a well planed live organic growing system can create plants bigger, healthier and more nutritious than any chemical regime in existence. This is not an advertising hype, nor an eco-nut rant. One thing however must be soberly understood. A well educated grower in traditional synthetic based program will outperform a novice organic grower. A good basic knowledge and a lot of care must go into an organic operation, just like all operations. Technical organic knowledge is being defined more and more everyday and should be kept up with for maximum benefits and results. Mycorrhizal benefits to plant growth can not be duplicated artificially. Mycorrhizal fungi are involved with a wide variety of important activities that benefit plant growth. The biological interplay is just too intense, complex and extensive to duplicate. It would be like trying to put together an organism with chemicals. It will always be way beyond human capacity and understanding. But with a new understanding of these limits the mystery of organics in nature can be applied with the same technical skill as trying to duplicate nature, with interesting results. A very good report was written  by Michael P. Amaranthus, Ph.D. originally appeared in The Spring 1999 issue of Florida Landscape Architecture...

Read More

Trichoderma | Astonishing Fungi

Trichoderma |  Astonishing Fungi

Trichoderma Fungus General Description The fungus Trichoderma is a filamentous, free-living fungi that are common in most soils and root ecosystems worldwide. Trichoderma have been found in prairies, forests, salt marshes, desert sands, lake water, dead plant material, seeds and air. They are also found in living roots of virtually any plant (1). Biocontrolfungi of Trichoderma have developed an astonishing ability to interact, both parasitically and symbiotically, in a variety of substrates, plants and with other microbes (2,3). Today Trichodermas is used more extensively in agriculture than any other single microbe. There are many effective Trichoderma species. So far, there are only 7 important Trichoderma species used commercially but more are being added to the list every year. Trichoderma asperellum Trichoderma harzianum Trichoderma hamatum Trichoderma koningii Trichoderma longibrachiatum Trichoderma pseudokoningii Trichoderma viride Trichoderma Fungus Mode of Action Trichoderma’s first claim to fame a few years ago was being a microbial predator, highly antagonistic of other fungus. They are specialists at killing other fungi with a  toxin. They then consume their prey by dissolving them with an exudent of lytic enzymes. This predatory behavior has led to their use to control other fungi plant disease. Interestingly enough it does not seam to have a negative influences over mycorrhizal fungi. Mycorrhyzal is another very beneficial fungus in the rhysophere. Cornell University’s recent research is quite interesting. It has found that Trichoderma’s disease control function is only the tip of the iceberg. In actuality, Trichoderma has a quite well defined symbiotic relationship with plant roots. They not only inhibit other fungus but supplying nitrogen to plant roots much like mycorrhizal fungus Trichoderma establish robust and long-lasting colonizations of root surfaces and penetrate into the epidermis and a few cells below this level. It then release different compounds that induce localized or systemic resistance responses. This explains their lack of pathogenicity to plants. These root–microorganism associations cause substantial changes to the plant proteome and metabolism. A recent discovery in several labs is that some strains induce plants to “turn on” their native defense mechanisms gives the impression that Thrichoderma will also control pathogens other than fungi. Plants are protected from numerous classes of plant pathogen by responses that are similar to systemic acquired resistance and rhizobacteria-induced systemic resistance. Trichoderma Fungus Mode of Application Trichoderma is normally supplied as a culture developed on softened rice. Place a kilo of this inoculated rice in a pale of de-chlorinated water along with 5ml of any available surface tension breaker. Let it sit for an hour or so as to let the rice soften further. Grind the rice between your hands to liberate the fungus from the rice. Do this grinding for a few minutes until the Trichoderma is practically all washed off of the rice. The rice will be a much lighter shade of blue-green at this point. Strain the liquid in a fine meshed food strainer to take out the larger chunks of rice. This is important only if you are going to be spraying the liquid on the phylosphere of the plants for fungal control, so the spray head doesn’t clog. If it is to be applied as a drench on roots, obviously there is no need for pre-straining. References 1. Monte, E. 2001. Understanding Trichoderma: Between biotechnology and microbial ecology. Int. Microbiol. 4:1-4. 3. Harman, G. E., and Kubicek, C. P. 1998. Trichoderma and Gliocladium, Vol. 2. Enzymes, Biological Control and Commercial Applications. Taylor & Francis, London. 3. Kubicek, C. P., and Harman, G. E. 1998. Trichoderma and Gliocladium. Vol. 1. Basic Biology, Taxonomy and Genetics. Taylor & Francis,...

Read More