STRATEGY FOR ENSURING BIOSECURITY OF NATURAL AND ECONOMIC SYSTEMS AS AN EXAMPLE OF THE CULTURE OF RATIONAL NATURE MANAGEMENT

The article presents an example of the implementation of the bioprotection strategy for cultivated phytocenoses. Vegetable crop losses due to pests are currently increasing. The mass infestation of the diamondback moth in vegetable agrophytocenoses in the Caucasus region poses a serious agricultural problem. Therefore, control measures against this phytophage become critically necessary. Our work reveals the importance of bacterial strains of the genus Bacillus from local ecosystems as microbiological pest control in vegetable agrophytocenoses. Within the integrated pest management system, unlike chemical insecticides, significant attention is now given to the application of bacterial insecticides of the Bt type, which are safe for humans and the environment. The isolation of bacteria of the Bt-type from dead larvae on nutrient media was performed under laboratory conditions, according to the methodological manual [21,35]. The detection of insecticidal crystalline inclusions in the bacterial smear was carried out according to the recommendation [15]. The sizing of vegetative cells, formed colonies, endospores, and crystalline particles of the isolated strains of the Bt was performed using an ocular micrometer. The biological efficacy of the insecticides was calculated using the Abbott's formula. The results of the experiments were subjected to statistical analysis [2,6]. The three strains of the Bt (BtHK-22, BtMS-49, BtAS-87) isolated from the biocoenosis differed from each other in the morphometric indicators of vegetative cells, formed colonies, endospores, and crystalline particles, as well as in the characteristics of carbon source utilization. The culture fluids produced individually based on the aforementioned strains, with the titer of 300 million spores/ml, demonstrated high biological efficacy (92.6–97.8% on average) against low-instar (I–II) larvae of the diamondback moth under laboratory conditions and 7 days after spraying in cabbage plantations. Statistical data confirmed that the results of the experiments are accurate and there is no significant difference between the biological efficacy indicators demonstrated by the local Bt-type culture fluids and the standard reference commercial Lipocid. Culture fluids with the titer of 300 million spores/ml will be recommended for application in farm enterprises as effective control measures against diamondback moth larvae. The culture fluids produced based on the Bt-type bacterial strains isolated from the biocoenosis, which differ from each other in certain morphological and physiological characteristics, with the titer of 300 million spores/ml, demonstrate high biological efficacy against low-instar diamondback moth larvae under laboratory conditions and in cabbage plantations. The density of diamondback moth larvae in the cabbage plantations was within the economic threshold of harmfulness for this pest. Statistical indicators confirm that the results of the experiments are accurate and there is no significant difference between the biological efficacy indicators demonstrated by the bacterial culture fluids of the Bt-type and the standard reference Lipocid against diamondback moth larvae. The bacterial strains used for bioprotection of agrophytocenoses are environmentally friendly and safe for human health. The results and conclusions of the study demonstrate the high effectiveness of biological pest control measures for vegetable plants. Furthermore, the work aims to rationalize (biologize) the management of biological resources to reduce dependence on commercial pest control products for cultivated phytocenoses.