It has been determined catalytic activity of cholinesterases for several insect species (Apanteles glomeratus L., Coccinella septempunctata L, Rhopalosiphumpadi L. and Pieris brassicae L.) that varies in norm from 57 to 199 mmol/hour per 1 gr. It has been calculated the constants of bimolecular interaction (K ii ) for insecticides Aztek, Mavric and Bi-58 new with cholinesterase of the insects. It occurred to be the most sensitivity to Bi-58 new is peculiar to this ferment in Coccinella 7-punctata L. K ii (4.54 ± 0.23) 10 4 ; whereas cholinesterase of Rhopalosiphum padi L. is the least sensitive to Aztek -K ii (2.9 ± 0.14) 10 5 . Determination of anticholinesterase action coefficient has revealed the value of this indice 118.9 for the preparation Aztek in the system "Rhopalosiphum padiCoccinella 7-punctata". Supposedly, anticholinesterase activity of Aztek is the base of its mechanism action on above-mentioned species of insects.

Goal. To study the toxicity of the modern variety of insecticides from different classes of chemical substances at the level of the mean concentration (СК50, %) of the active substance for the common cereal aphids, cabbage flea, rape blossom weevil, common spider mite. Based on these data to determine the rate of resistance of natural populations of these species of phytophagous arthropods to insecticides. Methodology. The sensitivity of phytophagous arthropods was studied on natural populations collected on crops of winter wheat, canola, soybeans in the Kiev region in 2015—2018. For the poisoning of cereal aphids and mites using the method of immersion of the populated lists wheat and soybeans, and flea beetles and pollen beetle — dip them in a gauze bag for 3 seconds in the appropriate solution of insecticides. Were taken 24 hours after poisoning. Toxicological parameters were calculated by using Proban. Results. Identifies the different sensitivity of the natural arthropod populations to current insecticides. In terms of the mean concentration (СК50, %) of the active substance rapeseed pollen beetle were most sensitive to Configure, while the rest of the drugs is almost the same. Over the years research is more resistant to Decis Profi turned ordinary spider mites. This pest was a higher resistance. Conclusions. The sensitivity of arthropods to insecticides of different chemical classes depends on the characteristics of the pest and the properties of the drug. Indicators of resistance are determined by the biology of the phytophage and terms of use of insecticide. The highest PR was observed for polyvoltine species (aphids, mites). Low levels of resistance to phytophagous pyrethroid insecticides can be explained by two factors: a smaller volume of use or reversion (return of chuvstvitelnosti to the initial level).

Goal. To substantiate and develop an anti-resistant system of protection of crops and perennials from harmful arthropods. Methods. The sensitivity of phytophages on natural populations collected on winter wheat, soybean, and rapeseed crops was determined by various methods of their poisoning: immersion of insects on inhabited plants, immersion of insects in gauze bags for 3 seconds. in a suitable solution of insecticide. The methods are based on the study of the pest’s response to a series of doses of the drug — from the minimum, causing mortality of 5—10% of normal-sensitive individuals, to the maximum (mortality of 90% or more). Toxicological parameters were calculated using the PROBAN program. Results. Different sensitivity of natural populations of arthropods to modern insecticides is revealed. Techniques for the rational use of insecticides populations and the use of alternative biological and immunological methods. Conclusions. An effective measure to prevent and inhibit the formation of resistant populations of harmful arthropod species to insecticides is an anti-resistant plant protection system. It includes monitoring the resistance of natural populations of harmful phytophagous species, identifying the type of resistance and the rational use of chemicals.

Goal. Ecological and toxicological substantiation of improving the chemical protection of agricultural crops and perennial plantations from harmful arthropods based on the updated assortment of insectoacaricides, the properties of chemicals and the characteristics of harmful insect and mite species in the technology of growing strategic crops. Methods. The sensitivity of phytophages was investigated on natural populations collectedё on crops of certain crops and determined by various methods of poisoning adopted in toxicology. The coefficient of selectivity of the insecticide in the phytophage — entomophage system was calculated by the ratio CK50 , % a.v. for phytophage to SC50 , % a.v. for an entomophage. The effect of urea on the properties of working solutions of chemical and microbiological preparations was studied in their mixture using special techniques. Results. Studies have shown different susceptibility of natural arthropod populations to modern insecticides, which have different selective effects on entomophages. The selectivity factor ranged from 15 to 560. Improved anti-resistance system to protect crops from harmful arthropods. The information on the possibilities of joint application of insecticides of different nature with Urea in a single technological process is generalized, which leads to a significant reduction in the evaporation of drops of solution from the treated surface. Conclusions. Expansion of the range of pesticides, especially those with a different mechanism of toxic action, makes it possible to prevent or slow down the development of resistance in arthropods to insecticides. An improved anti-resistance system for protecting agricultural crops from harmful arthropods provides a decrease in the toxic load on the agrocenosis and a reversal of resistance to the initial parameters. Urea is an active anti-evaporation agent for working solutions of insecticides of various nature.

A study of the toxicity of insecticides in relation to colorado potato beetle by the method of topically treating of insects was performed. Using the method of probit analysis with the aid of computer program LD50 is the LD95 were determined. The advantages of this method compared to others are described.