Beauveria bassiana Strain GHA kills insects, non-selectively. The target pests are several varieties of the following: scarab beetles, leaf-feeding beetles (including Colorado potato beetle), whitefly, aphids, thrips, psyllids, mealy bugs, leafhoppers and plant hoppers, weevils, plant bugs (including chinch, lygus and flea hoppers), borers, leaf-feeding insects, grasshoppers, locusts and Mormon crickets, stem-boring lepidoptera (including European and Southwestern corn borer).
How to Use: The liquid and powder form of the strain can be combined and spread with compost teas or compost extracts. Make sure the temperature is between 50 to 85 degrees F. Effectiveness is in two days. Then repeat if needed. Since it is not a pathogen to humans, harvests can generally commence a day or so after application. Comply with the directions on the bottle.
Where to Get and Costs: Any hydroponic store carries it or knows where to order it. It comes in two forms, a liquid form that needs to be refrigerated and a powder form. The cost is about $130 per quart of the liquid form. One quart covers about an acre once diluted. The liquid form has an expiration date. The powder from (22WP) has a long shelf life.
BotaniGard 22WP, Wettable Powder Mycoinsecticide (http://www.bioworksinc.com/products/shared/botanigard.pdf)
Mycotrol O (BioWorks) Beauveria bassiana strain GHA ( http://www.bioworksinc.com/products/mycotrol-o.php)
BotaniGard (BioWorks) Beauveria bassiana strain GHA (http://www.bioworksinc.com/products/botanigard-es.php)
(Laverlam International) Beauveria bassiana strain GHA (http://www.laverlamintl.com/)
Warnings: This is basally a non-selective pesticide. It also kills beneficials….. i.e. wasps, honey bees, etc…
Beauveria bassiana is a fungus that is commonly found in soils worldwide. 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. There are two commonly used strains, GHA and ATCC 74040. These products are produced through fermentation. The spores (conidia) are extracted and formulated into a sprayable product and powder.
Beauveria bassiana kills the pest by infection as a result of the insect coming into contact with fungal spores. An insect can come into contact with the fungal spores in several ways: by having the spray droplets land on its body, by moving on a treated surface, or by consuming plant tissue treated with the fungus (the latter is not a major method of uptake). Once the fungal spores attach to the insect’s skin (cuticle), they germinate sending out structures (hyphae) that penetrate the insect’s body and proliferate. It may take 3-5 days for insects to die, but infected cadavers may serve as a source of spores for secondary spread of the fungus. High humidity and free water enhance activity of the conidia and the subsequent infection of the insect. Fungal spores are readily killed by solar radiation and infect best in cool to moderate temperatures.
Because the spores may have a short life, it is important that the spray or spray deposit has sufficient opportunity to contact the insect. Therefore, good coverage is essential with a large number of droplets containing a high concentration of spores. Care should be taken to apply the material to the undersides of the leaves or wherever the pest species primarily occurs. For insects that bore into a plant (e.g. the European corn borer), control will be very difficult. For best results, applications should be made during the early growth stages of the insect before much damage has occurred, as it may take several days for the insect to die. Speed of kill depends on the number of spores contacting the insect, insect age, susceptibility and environmental conditions.
One formulation of B. bassiana, Mycotrol™, is reported to be sensitive to high temperatures with best results at application temperatures between 70 and 80°F. Slow growth at warmer temperatures may make this a poor option for growers in southern states.