In the 21st century, many biopreparations based on entomoparasitic (entomopathogenic) fungi have appeared on the global market. Several similar developments have been registered in Russia in recent years.

While these commercial products are sometimes advertised as something previously unknown to consumers, it should be noted that the first practical steps in this direction were actually taken in the second half of the 19th century by the eminent microbiologist I.I. Mechnikov and his associate I.M. Krasil'shchik.

The article "On the Diseases of Grain Beetle Larvae" (Mechnikov, 1879) outlined the very idea of ​​using fungal pathogens of insects as a "biological weapon" against plant pests. Seven years later, the first worldwide publication on the production of an insecticidal biopreparation for plant protection was published: "On the Industrial Production of Infectious Fungi for the Purpose of Spreading Them Among Harmful Insects" (Krasil'shchik, 1886). The producer of this truly innovative development was the microscopic fungus Metarhizium anisopliae.

Currently, over 1,000 species of fungi that attack insects, mites, and nematodes are known worldwide; of these, approximately 20 are used as pest biocontrol agents (Faria, Wright, 2007). Fungal biopreparations are currently most widely industrially produced in China, Brazil, Argentina, and Mexico, where they are used annually on tens of thousands of hectares of agricultural land and for forest protection.

The construction of hundreds of large greenhouse complexes in the former USSR in the 1970s and 1980s effectively created vacant ecological niches, which were quickly occupied by herbivorous organisms with rapid growth rates and high reproductive potential: greenhouse whiteflies, several species of aphids, thrips, spider mites, and root-knot nematodes. In this regard, in the 1980s, several hundred small-scale biofactories (industrial biolaboratories) were established in many regions of the country at plant protection stations and directly in greenhouses. These facilities produced fungal biopreparations against pests (Ashersonia against whiteflies, later Verticillin against them and aphids, and Boverin against thrips) and pathogens (Trichodermin against root rot pathogens, Ampelomycin against powdery mildew).

It must be acknowledged that, based on global experience, a key weakness in the development of biomethods in practice is the strong dependence of the vital activity of all bioagents (arthropods, entomo- and acariphages, parasitic and antagonistic microorganisms) on environmental conditions. Thus, a temperature deviation of just a few degrees can dramatically impact effectiveness.

A weak point of parasitic fungi is that high humidity during the first 16-24 hours after application of mycoinsecticides is necessary for the germination of their infectious spores (conidia or blastospores) and penetration of the host's body through the integument. This explains why such biological preparations are quite competitive with chemical insectoacaricides and nematicides in countries (regions) with warm, humid climates or in greenhouse conditions.

However, many previous barriers to the wider use of fungal biopreparations can be overcome with the current level of scientific development by selecting producer strains not only with high activity (virulence) but also with increased drought resistance, by incorporating additives into the formulations that accelerate spore implantation, protect them from desiccation, and protect them from the harmful effects of insolation, prolonging their viability during storage, and so on. The "safety margin" of biopreparations can also be increased by using well-designed compositions of several species and/or strains, differing in both their environmental preferences (e.g., different temperature optima), and their spectrum of activity against pests from different taxonomic groups.

The above considerations formed the basis for the development of the bioinsecticide Lovchiy, SP (dry powder) at AgroBioTekhnologiya LLC, which is undergoing state registration. Its active ingredient is infectious spores with a total titer of at least 6 x 108 per 1 g of four species of entomoparasitic fungi: Beauveria bassiana, Akanthomyces muscarium, Cordyceps farinosa, and Metarhizium anisopliae.

Since 2021, state trials of the biological product have been conducted against various pests both in the field and in protected soil: against aphids on tomatoes, thrips on eggplant, and greenhouse whiteflies on cucumbers (see Table 1).

Table 1. Biological effectiveness of the insecticide Lovchiy, SP on greenhouse whitefly

Another new development by AgroBioTechnology LLC is the bioinsecticide Endobacterin, Zh (liquid), which is based on a composition of three strains of different serotypes of the entomopathogenic bacterium Bacillus thuringiensis with a total cell titer of at least 109 cells per ml.

In addition to live bacterial spores, the active ingredients of this biopreparation are also its endotoxins (δ-endotoxin) and exotoxins (α-exotoxin, or phospholipase C, β-exotoxin), contained in a fermented nutrient medium. Thus, when using this biopreparation, insect mortality is due to the combined action of the live bacteria and its metabolites. Importantly, these toxins are harmless to humans and warm-blooded animals and pose little risk to bees, and their rate of lethal action on phytophagous arthropods is comparable to that of chemical insectoacaricides.

Thanks to the composition of different B. thuringiensis serotypes, which differ in their specialization to insects from different orders and the production of specific metabolites, the product exhibits high activity against a wide range of phytophages. These include young and middle-instar caterpillars of Lepidoptera from various families, leaf beetle larvae, weevils, thrips, many aphid species, and others. The product also targets mites, many of which cause serious damage to plants in protected soil: spider mites (common, red, etc.), brown bryobid mites, tyrophagids (elongated rot mites), and eriophyids (tomato rust mites) (Akhatov et al., 2013).

Tables 2-4 below present the product's effects on selected pest species in protected soil.

Table 2. Biological effectiveness of the insecticide Endobakterin, G against tobacco thrips on cucumbers in protected ground

Table 3. Biological effectiveness of the insecticide Endobacterin, G against melon aphids on cucumbers in protected ground

Table 4. Biological effectiveness of the insecticide Endobacterin, G against greenhouse whitefly on tomatoes in protected ground

In addition, Endobakterin, G biopreparation was tested against spider mites and lepidopteran larvae on vegetable crops, as well as against thrips on roses and other flower crops in protected soil conditions. Targeted trials of the biopreparation against tomato rust mites and tomato leaf miners have not yet been conducted, but a "collateral" lethal effect on these pests has been observed.

These results allow us to draw preliminary conclusions about the high efficacy of the new bioinsecticides against a range of pests in protected soil conditions on both vegetable and flower crops. 

Boris Aleksandrovich Borisov, Head of the Microbiological Plant Protection Laboratory, AgroBioTekhnologiya LLC

Viktor Vladimirovich Bukreev, Agronomist-Phytopathologist, AgrobioTekhnologiya Research Center

Viktor Nikolaevich Yuvarov, Leading Agronomist-Consultant, AgroBioTekhnologiya LLC

Dmitry Andreevich Shlykov, Agronomist-Consultant, AgroBioTekhnologiya LLC