Efficacy of some insecticides against Rhodococcus perornatus (Hemiptera: Coccidae) on the oil-bearing rose (Rosa damascena Miller)

The oil-bearing rose (Rosa damascena Miller) is the most important essential oil crop in Bulgaria. In May 2023 in rose plantations located in the region of Zelenikovo village the rose soft scale Rhodococcus perornatus (Hemiptera: Coccidae) was found in high density of 5% infested rose bushes (Cockerell & Parrott, 1899). The rose plantations are growing within the conventional farming. Two chemical (Closer – 0.02%, 0.04% and Sivanto prime – 0.05%, 0.1%) and one biological (Naturalis – 0.1%, 0.2%) insecticides were tested against the rose soft scale. All tested products showed better results in higher concentrations. Closer indicated the fastest initial action. In the concentration of 0.04% on the 1stday after the treatment its efficacy was 100%. Sivanto prime in the concentration of 0.1% on the 5th day after the treatment showed an efficacy of 100%. The biological insecticide Naturalis had a slower action and in the concentration of 0.2% on the 7th day after the treatment its efficacy was 90%.