MEASURES OF CHEMICAL CONTROL OF PENTATOMID EURYGASTER UNDER THE CONDITIONS OF NIZHNY DON
The results of studies on the harmfulness of larvae of pentatomid eurygaster (grain bug) for winter wheat crops are suggested. The quantitative relationship between the pest number and grain damaging has been established. The effect of grain damaged by larvae of the above pest, on the mass of1000 grains and gluten quality has been determined. It is ascertained that with the bug larvae number being about 5–6 specimen/m2 and grain damaging of about 2%, the gluten quality remains within the standard limits, while when grain damage is more than 3% its quality is lowered from the 2nd grade (slightly satisfactory) to the 3d grade (slightly unsatisfactory). The necessity to revise the regulations concerning the threshold of harmfulness and indices of grain damage by the above bug pest is substantiated. The efficiency of preparations containing organophosphorus compounds or neonicotinoids against the grain bug imago in the process of crops treatment at the ear formation stage, or insecticides of the group of synthetic piretroids used at the milk ripeness stage is shown. Their biological effect, when used against the bug larvae on the 21st day of registration is not inferior to the preparations of other chemical groups, and on the 3d and 7th days it is even slightly superior as compared with other preparations.