- Beauveria bassiana is a ubiquitous fungus that infects a wide range of insects. Different strains of the fungus have been obtained from various insects and in some cases mass produced and commercialized.
- Although the species is known to infect a wide range of insects, most strains are relatively host-specific.
- In greenhouses, the GHA strain is most commonly used (as BotaniGard®). GHA stands for ‘Grass Hopper Active’ as the strain was originally developed to control grasshoppers and locusts. In 2014, another strain was registered, ANT-03 (BioCeres®) which was originally isolated from tarnished plant bug.
- The commercial products are mass produced by fermentation on solid substrate, the conidia (spores) harvested and formulated into sprayable products.
- Beauveria bassiana will infect and kill a wide variety of soft-bodied insect pests such as whiteflies, thrips and aphids. Some studies indicate effects on mite pests as well. However, Beauveria has different efficacies on these pests. It can be a very effective product on whitefly and thrips, but strains are far less effective on aphid pests.
- It is very specific to insects; it will not infect plants.
- It is compatible with many beneficials (consult Side-Effects guides under External Links).
- There is no limit to the number of times the fungus can be applied during a season; sprays are often applied weekly in a preventative program.
- It can be used as a stand-alone control agent or within a spray rotation. It is compatible with many insecticides and may be tank-mixed with some products. It is also compatible with some fungicides, although a pre- or post-application period ranging from 2-4 days may be required for some products (see producer’s website for up to date information)
- The fungus has a unique mode of action and is thus effective against insecticide-resistant pests. It is an excellent product for use in a resistance management program.
- As infected insects die, they commonly change colour to pink or brown as the body cavity is filled with the fungus; white outgrowth of the fungus from the body is rarely observed under ‘natural’ conditions.
- It is considered a reduced-risk product, safe for workers and the environment, with a short Restricted Entry Interval.
- Products should ideally be stored cool (ca. 10°C) and dry; it is recommended that the product should be stored for no more than 9 months if held at room temperature (25°C), no more than 3 months if held at 35°C. Do not contaminate unused product with water and keep container tightly closed.
- Remember – it is a living organism and needs to be stored and handled appropriately to maintain viability and obtain the best results.
- B. bassiana infects insects directly through the body wall when conidia contact and become attached to the cuticle. The conidia germinate and penetrate the insect body wall by a combination of mechanical force and production of enzymes that digest the cuticle. The fungus will then grow inside the insect’s body, and will eventually kill the host.
- It may take several days for death to occur.
Recommendations for Use
- bassiana GHA is registered in Canada as wettable powder (BotaniGard 22WP) and emulsifiable concentrate (BotaniGardES) formulations.
- bassiana ANT-03 is registered as Bio-Ceres G WB and Bio-Ceres G WP.
- Both Canadian registered products are formulated to be applied as high volume sprays.
- Preventative application of Beauveria when insect numbers are low provides the most effective control.
- Be sure to shake the ES container vigorously before using to suspend the conidia.
- For either product, fill the spray tank with half the desired amount of water and agitate; add appropriate quantity of product, allow to mix thoroughly and then add the remainder of the water.
- Do not use hot water or leave spray mix standing for more than 2 h prior to use. Do not stand a spray tank in direct sunlight or heated area for an extended period prior to use. Do not store a spray mix overnight and use the next day.
- The fungus works as a contact insecticide so thorough spray coverage is essential to obtain control. For whiteflies, sprays need to be directed into the foliage and specifically under the leaves.
- Spray to wet the leaves but not to the point of run-off; as with all pesticides, spraying to run-off can actually reduce the amount of active product that remains on the leaf as material may run with the leading edge of the drip and be lost or concentrated along the leaf margin.
- Three sequential applications at 7-d intervals are recommended when pest pressures are low, with repeat applications as pest pressures persist thereafter; spray interval may be reduced to 3-5 days if pest pressures are high, and six sequential sprays may be required to achieve control. Also consider rotating with a standard insecticide to obtain quick ‘knock down’ before resuming a preventative spray regime with Beauveria.
- The WP formulation of BotaniGard is registered in Canada for control of aphids, thrips and whiteflies on greenhouse ornamentals and vegetables at 250-1000 g/400L water. The ES formulation is registered for application at 0.5-2.0 L/400L water. Rates used depend on the pest and the severity of the infestation.
- For practical use of this fungus in insect control, it is sensitive to temperature extremes above 30-32oC. Insect infection is promoted under humid conditions, (Note that at the leaf surface, humidity is higher than ambient conditions) and moderate temperatures.
- Infected whitefly larvae or pupae will become discoloured when infected, turning brown or pink.
- BotaniGard is compatible with many of the beneficials used in floriculture crops; consult guides referred to under ‘External Links’ for more details.
- In vegetable crops, the product should not be applied when bees are actively foraging (pollinating) to minimize any potentially harmful effects; hives should be covered if possible when sprays are being made.
- For all pests, it is beneficial to periodically monitor spray coverage using water- or oil-sensitive spray cards placed throughout the crop. Recovery of cards after spraying will demonstrate the degree of spray coverage obtained in different areas of the crop, e.g., under leaves, top/bottom of plant, etc.
- The fungus will not infect whitefly scales parasitized with Encarsia or Eretmocerus and has been successfully used together with predatory mites for thrips control.
- Chandler, D., Davidson, G., Jacobson, R.J., 2005. Laboratory and glasshouse evaluation of entomopathogenic fungi against the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), on tomato, Lycopersicon esculentum. Biocontrol Science and Technology 15: 37-54.
- Wraight, S.P., Carruthers, R.I., Jaronski, S.T., Bradley, C.A., Garza, C.J., Galaini-Wraight, S. 2000. Evaluation of the entomopathogenic fungi Beauveria bassiana and Paecilomyces fumosoroseus for microbial control of the silverleaf whitefly, Bemisia argentifolii. Biological Control 17: 203-217.
- Jandricic SE, Filotas M, Wraight SP. Pathogenicity of conidial-based preparations of entomopathogenic fungi against the greenhouse pest aphids Myzus persicae, Aphis gossypii and Aulacorthum solani (Hemiptera: Aphididae). Journal of Invertebrate Pathology 118: 34-46.
- Al-mazra’awi, M.S., Kevan, P.G., Shipp, J.L., 2007. Development of Beauveria bassiana dry formulation for vectoring by honey bees Apis mellifera (Hymenoptera: Apidae) to the flowers of crops for pest control. Biocontrol Science and Technology, 17, 733-741.
- Labbé, R.M., Gillespie, D.R., Cloutier, C., Brodeur, J., 2009. Compatibility of an entomopathogenic fungus with a predator and a parasitoid in the biological control of greenhouse whitefly. Biocontrol Science & Technology 19, 429-446.
- Zimmermann, G., 2007a. Review on safety of the entomopathogenic fungi Beauveria bassiana and Beauveria brongniartii. Biocontrol Science and Technology 17, 553-596.
- de Faria, M.R., Wraight, S.P., 2007. Mycoinsecticides and mycoacaricides: a comprehensive list with worldwide coverage and international classification of formulation types, Biological Control 43, 237-256.
- Ugine, T.A., Wraight, S.P., Sanderson, J.P., 2007. Effects of manipulating spray application parameters on efficacy of the entomopathogenic fungus Beauveria bassiana against western flower thrips, Frankliniella occidentalis, infesting greenhouse impatiens crops. Biocontrol Science and Technology 17, 193-219.
- Brownbridge, M., 2006. Entomopathogenic fungi: Status and considerations for their development and use in integrated pest management. Recent Research Developments in Entomology 5, 27-58.
- Heinz, K.M., Van Driesche, R.G. and Parrella, M.P. 2004. Biocontrol in Protected Culture (eds: K. M. Heinz, R.G. Van Driesche and M.P. Parrella), Ball Publishing, Batavia, Illinois, 552 pp.
- Kapongo, J.-P., Shipp, J.L., Kevan, P.G., Broadbent, A.B., 2008. Optimal concentration of Beauveria bassiana vectored by bumble bees in relation to pest and bee mortality in greenhouse tomato and sweet pepper. BioControl, 53, 797-812.
- Kapongo, J.-P., Shipp, J.L., Kevan, P.G., and Sutton, J.S., 2008. Co-vectoring of Beauveria bassiana and Clonostachys rosea by bumble bees (Bombus impatiens) for control of insect pests and suppression of grey mould in greenhouse tomato and sweet pepper. Biological Control, 46, 508-514.