An experimental trial was conducted to determine the pathogenicity of Beauveria bassiana strain 202 (Bb-202) against multiple targeted sucking insect species that are serious pests of crops and ornamental plants. The insect species, Myzus persicae Sulzer (Hemiptera: Aphididae), Jacobiasca formosana Paoli (Hemiptera: Cicadellidae), Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), and Stephanitis nashi (Hemiptera: Tingidae) were exposed to conidia of B. bassiana at rates of 1.0 × 10², 3.5 × 10³, 5 × 10⁴, and 6.75 × 10⁵conidia/mm² to determine the pathogenicity of B. bassiana. The fungal strain Bb-202 showed the highest pathogenicity to M. persicae and 100% corrected mortality observed in the treatments over 1.0 × 10²conidia/mm², followed by the J. formosana with the final corrected mortality of 86.6, 94.4, and 97.4% after 10 days of fungal inoculation with 3.5 × 10³, 5 × 10⁴, and 6.75 × 10⁵conidia/mm², respectively. The strain Bb-202 also showed good pathogenicity to B. tabaci and corrected mortalities of 77.9 and 81.1% were recorded when exposed to 5 × 10⁴ and 6.75 × 10⁵conidia/mm². Relatively weak pathogenicity was observed in S. nashi, in which the highest corrected mortality of 63.7% occurred at 6.75 × 10⁵conidia/mm². Accordingly, the LC₅₀and LT₅₀values of concentrations 1 × 10⁵, 1 × 10⁶, 1 × 10⁷, and 1 × 10⁸ conidia/ml were calculated for M. persicae, J. formosana, B. tabaci, and S. nashi that were determined as 6.7 × 10⁴, 1.3 × 10⁶, 3.6 × 10⁶, and 1.2 × 10⁷ conidia/ml and LT₅₀ was observed as 5.2~8.24, 5.1~6.6, 7.2~9.0, and 7.9~9.6 in days, respectively.

Poslušná J. Plachká E., Mazáková J. (2018): Influence of selected fungicides registered in the Czech Republic for winter oilseed rape on in vitro Sclerotinia sclerotiorum mycelial growth. Plant Protect. Sci., 54: 101-110.The baseline sensitivity of 55 isolates of Sclerotinia sclerotiorum, collected from oilseed rape in 6 regions of the Czech Republic, to selected fungicides was determined during the period 2013-2015. One single-component fungicide -Horizon (tebuconazole), and four multicomponent fungicides -Pictor (boscalid, dimoxystrobin), Efilor (boscalid, metconazole), Prosaro 250 EC (prothioconazole, tebuconazole), and Propulse (fluopyram, prothioconazole), were chosen as these are commonly used locally. The effect of each fungicide on the in vitro pathogen radial mycelial growth and EC 50 values for the respective fungicides were determined. The following MIC values were estimated; for the fungicides Horizon 250 EW, Efilor, and Propulse the mean MIC values ranged between 0.125 and 0.250 µl/ml, for Prosaro 250 EC ranged between 0.0625 and 0.125 µl/ml, and for Pictor ranged from 0.00781 to 0.01562 µl/ml. No strains of S. sclerotiorum resistant to the tested fungicides were detected and the growth of all isolates was fully inhibited at concentrations corresponding to their registered dose rates. The highest fungicidal efficacy on the collected S. sclerotiorum isolates was recorded for Pictor, followed by Prosaro 250 with an EC 50 value 0.05856 µl/ml and then the remaining fungicides Propulse, Efilor, and Horizon 250 EW (EC 50 values 0.07277, 0.07221, and 0.08519 µl/ml, respectively).