Biological control of Panaphis juglandis (Goeze, 1778) with some bioinsecticides in Bulgaria

Abstract

The efficacy of three bioinsecticides: the microbial Naturalis (Beauveria bassiana) and the botanical Pyrethrum FS EC (pyrethrin + sesame oil + soft potassium soap) and NeemAzal T/S (azadirachtin), approved for application in organic farming in Bulgaria, against the large walnut aphid Panaphis juglandis (Goeze, 1778) were studied under laboratory conditions. The best results from the tested products were for the microbial insecticide Naturalis (Beauveria bassiana). At a concentration of 0.2% the efficacy reached 46% on the 3^rd day, 70.3%, on the 5^th day and 91.5% on the 7^th day after the treatment. The preparation showed very good action in its low concentration (0.1%) – efficacy was over 65% on the 5^th day and 79.8% on the 7^th day after the treatment. Insecticides based on plant extracts did not show very good efficacy against Panaphis juglandis. The Pyrethrum insecticide, based on natural pyrethrins showed better action than azadirachtin based product NeemAzal T/S. The efficacy of Pyrethrum on the 7^th day after the treatment reached 86.9% at concentration 0.1% and 75.8% at lower concentration of 0.05%. The weakest action was shown by NeemAzal T/S. The efficacy was only 67.6% and 61.6% at concentration 0.5% and 0.3%, respectively.