SUBSTANTIATION OF SELECTION OF INSECTICIDES FOR THE PROTECTION OF WHEAT FROM THE SUNN PEST (<i>EURYGASTER INTEGRICEPS </i>PUTON)
The objective of this work was to substantiate the choice of the most efficient and environmentally low-hazardous insecticides for the protection of wheat from the Sunn pest. A comparative evaluation of the potential hazard of insecticides was performed by analyzing the physico-chemical and toxicological properties of active ingredients of only those insecticides that had been included in the catalogue of pesticides and agrochemicals authorized for use in the Russian Federation. It has been established that organophosphorus preparations possessed the least soil persistence. In the group of pyrethroids there were insecticides with both low and medium soil persistence. The most persistent preparations were those from the neonicotinoid group of compounds. By the volatility of active ingredients only imidacloprid was evaluated as a nonvolatile compound and thiamethoxam was moderately volatile. All other insecticides were volatile. In terms of toxicity to non-target species there were no insecticides with clear advantages by the main criteria. In the actual situation, the contamination of soil with pyrethroids is lower than with neonicotinoids and phenylpyrazoles, let alone the organophosphates. When the obtained data was compared with the maximum allowable concentrations (MAC) of insecticides in the soil, it was defined that the majority of preparations recommended for this purpose yielded the soil concentrations that did not exceed the MAC level, if used at the permitted rates of application. The use of dimethoate-based insecticides is accompanied by the deposition of the toxicant mass in the upper five-centimeter layer of the soil at the MAC or even higher levels. The author has calculated the period of degradation of dimethoate molecules in the soil. By the duration of its protective action, the level of hazard to non-target species, its biological effectiveness and cost parameters the Mospilan soluble powder (200 g/kg) has a significant advantage compared to other insecticides when used to protect wheat against the Sunn pest.