Role of neonicotinoid preparations for spike grain crop seedlings protection against click beetle and Frit fly larvae in Belarus

Recently, in winter and spring grain crops for pre-sowing seed treatment among the assortment of insecticides the preparations of insecticidal and insectofungicidal action based on neonicotinoids: acetamiprid, imidacloprid, clothianidin and thiamethoxam have been widely used. At the current stage of chemical method development of plant protection against harmful arthropods, neonicotinoids are rapidly developing and promising group of neurotoxic insecticides and having a fundamentally different mechanism of action on insects – they inhibit nicotine-acetylcholine receptors. Pre-sowing seed material treatment with insecticides protects the sown seeds, hypocotyls and aboveground plant organs against soil and intrastem pests. It is revealed that during the growing seasons of 2019–2021 in the experimental field, economically significant phytophages are lined click beetle (Agriotes lineatus L.) and Frit flies of autumn and spring generations (Oscinella spp.), indicating the study of their larvae number and harmfulness and measures allowing to control the vital activity of insects in agrocenoses conditions. Plants damaged by them lag behind in growth and die. Improving the range of effective preparations with different active substances used by the method of pre-sowing treatment of grain crop seeds to protect plants during germination against phytophages is an obligatory link in the technology of crops cultivation and one of the factors of their number effective control, what has determined the relevance of the choice of our research topic. Pre-sowing winter and spring cereals seed treatment with neonicotinoid preparations based on imidacloprid (Coyote, SC, Sidoprid, FSC, Tabu, WSC), acetamiprid (Leatrin, SC, Bagrets Plus, SC, Vershina Plus, SC) and thiamethoxam (Questor Forte, SC) have provided plant seedlings high protection against click beetle and Frit fly larvae damage. The results of studies conducted in 2019–2021 have shown that the effectiveness of preparations have varied by years depending on weather conditions and pests number before sowing and at seedlings stage. The indicators of winter grain crops plant damage reduction by wireworms have made 78,8–91,1 %, Frit flies 60,0–85,0 %, spring cereals – 80,0–91,6 % and 80,7–91,1 %, respectively. Through years of research the insecticides for seed treatment have helped to increase the stored grain yield of cereal crops, on the average, from 0,7 to 6,2 cwt/ha, or 1,0–13,5 %. The data obtained will serve as a basis for justifying protective measures to reduce the number and harmfulness of soil-dwelling and terrestrial pests in order to improve the phytosanitary situation in the agrocenoses of cereals.