Beauveria bassiana (strains ATCC 74040 and GHA)

Beauveria bassiana is an entomopathogenic fungus that serves as the core of many biological control products. Unlike chemical insecticides, it acts by infecting the insect host through direct contact with fungal spores (conidia).

Once landing on the insect's cuticle, the spores germinate. They release specific enzymes that break down the chitinous exoskeleton, allowing the fungal hyphae to penetrate into the host's body.

Inside the insect, the fungus grows rapidly, consuming internal tissues and producing toxic metabolites like beauvericin. This process eventually leads to the death of the pest.

After the insect dies, a white or yellowish mycelial growth appears on its surface. This layer produces a new generation of spores that can infect other insects, creating a secondary spread within the population.

Strains ATCC 74040 and GHA are highly valued for their stability and high virulence against a broad range of target pests, making them a cornerstone of modern integrated pest management.

These strains are highly effective against a variety of pests, including aphids, whiteflies, thrips, plant bugs, weevils, and various caterpillars. Some efficacy against spider mites has also been reported.

The fungus is primarily used on vegetables, greenhouse crops, fruit trees, and ornamental plants where chemical pesticide residues need to be minimized or avoided.

It is particularly effective in controlled-environment agriculture, such as greenhouses, where consistent humidity levels create favorable conditions for spore germination and infection.

This biological agent is an essential tool for organic farming and conventional growers looking to manage resistance issues associated with traditional chemical insecticides.

By targeting the pests at the nymph and adult stages, the fungus helps to disrupt the life cycle and suppress population explosions in various agricultural settings.

Recommended application rates typically range from 0.5 to 2.0 liters (or kg) per hectare, depending on the formulation and the specific crop being protected. Always follow the label instructions provided by the manufacturer.

Applications are most effective when carried out in the early morning or late evening, as ultraviolet radiation from direct sunlight can reduce the viability of the fungal spores before they infect the host.

For preventative control, sprays should be repeated every 10–14 days. If the pest population is already high, shorter intervals of 5–7 days are recommended to ensure comprehensive coverage.

Optimal environmental conditions include temperatures between 18°C and 28°C (64°F–82°F) and relative humidity levels of at least 60% to support the rapid development of the fungus.

Thorough spray coverage is vital, especially on the undersides of leaves where many pests congregate, as contact is required for the infection process to begin.

Do not tank-mix with chemical fungicides. Fungicides are designed to kill fungi and will neutralize the biological activity of Beauveria bassiana, rendering the application useless.

Storage must be in a cool, dry, and dark place. Prolonged exposure to high heat or direct sunlight will degrade the spores and significantly reduce the shelf life and efficacy of the product.

Avoid applications during periods of extreme drought or low humidity, as these conditions significantly inhibit the germination of the fungus on the insect's surface.

While the product is generally safe for mammals, operators should use standard protective equipment like masks and gloves to avoid potential irritation caused by inhaling or touching high concentrations of spores.

Biological insecticides are not "knock-down" agents; they take time to work. Growers should expect the mortality of pests to occur over 3 to 7 days, meaning treatments should be timed ahead of significant pest outbreaks.