Residual efficacy of the insecticide deltamethrin, an EC formulation containing 25 g/L AI + 225 g/L PBO (piperonyl butoxide synergist), against lab populations of Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum and Sitotroga cerealella was investigated in the laboratory by applying product water solutions (0.25 mg AI/kg) to wheat grain (at 25±1°C and 60±5% r.h.). Adult mortality on 0, 7, 14 and 30 days old deposits was estimated after 2, 7 and 14 days of exposure to treated wheat grain and additional 7 days of recovery. Progeny reduction (PR, %) was also assessed. After 2 days of exposure to deposits of all ages, deltamethrin caused only 0-10% mortality of coleopterans (up to 37% after the recovery period) and 23-30% of S. cerealella, while mortality before and after recovery from 14 days of exposure was 95-50% for S. oryzae, 97-100% for R. dominica, 99-100% for T. castaneum and 100% for S. cerealella. Progeny production of S. oryzae was highest after parents contacted with 14 days old deposit of deltamethrin (PR, 76%), and lowest after contact with fresh deposit (PR, 95%), while R. dominica and T. castaneum had no progeny on any deltamethrin deposit age in wheat (PR, 100%), and S. cerealella had only a very low progeny (PR, 99%). The results showed that the synergised deltamethrin, applied at 0.25 mg/kg in wheat grain, is a highly effective insecticide for storedproduct insect control, while a higher dose is required for successful residual control of S. oryzae.

In the field trial conducted in 2020 at the locality of Mačvanski Metković (municipality of Bogatić, Serbia), the efficacy of products based on bifenazate and pyridaben in the control of the plum rust mite (Aculus fockeui) on sour cherry was examined. Product Acramite 480 SC (bifenazate) was tested in two application rates, 0.375 l/ha and 0.75 l/ha, while Sanmite 20 WP (pyridaben) was applied in an amount of 500 g/ha. The experiment was performed according to the standard, partially adapted EPPO method for testing the efficacy of acaricides in the control of spider mites in fruit orchards. Based on trial results, it can be concluded that the efficacy of bifenazate was different depending on the application rate of the product. The efficacy of this compound applied in the amount of 0.75 l/ha of the product Acramite 480 SC was very high and ranged between 94.85% and 98.96%, respectively. The same product in the amount of 0.375 l/ha showed low efficacy, which ranged from 55.27% to 88.22%, respectively. The efficacy of pyridaben was high in all evaluations (90.43% - 95.25%).

In a laboratory screening test, the effects of acetamiprid, lambda-cyhalothrin, abamectin, phosmet and chlorantraniliprole on ragweed leaf beetle (Ophraella communa LeSage) were examined. The aim was to investigate their selectivity for this species in crops and orchards where they are used, and to test the possibility of their application in case of its appearance on cultivated sunflower in order to prevent damage. Commercial insecticidal formulations were used, in doses recommended for the control of a related species, Colorado potato beetle. The experiment was performed according to a standard, partially adapted method for determining the sensitivity of the Colorado potato beetle to insecticides. Based on the test results, it was determined that lambda-cyhalothrin, abamectin and phosmet are non-selective for this species, causing high mortality of individuals (100%). Weaker effects (mortality of 88.16% to 89.39%) were shown for acetamiprid, and its effect on this insect species can be assessed as weakly selective. Chlorantraniliprole showed some selectivity and very poor efficacy in O. communa control (mortality of 40.79% to 45.45%). Its application in crops and orchards would not significantly reduce the number of ragweed leaf beetles.