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Rezistence škůdců řepky k vybraným účinným látkám insekticidů
Hajda, Tomáš
Resistence population of pollen beattle on selected locations of Moravia and Silesia were observed during the 2017. Beattles were taked off in the field during spring and their sensitivity to insecticides active substances indoxacarb, chlorpyrifos, thiacloprid, tau-fluvalinate, cypermethrin and lambda-cyhalothrin were tested in laboratory. Tested using methods of IRAC – 11, 21, 25 and 27. Mortality of beattles at various concentrations of active substances was evaluated after 24 hours. Levels of resistance were changed for individual location.
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Neonikotinoidy ve vodních ekosystémech a jejich vliv na necílové organismy
STROUHOVÁ, Alžběta
Neonicotinoids are one of the newesst class of pesticides, used in agriculture like insecticides. The first neonicotinoids has been used since the early 1990s, they become very popular and widely used worldwile for their low toxicity for vertebrates. Neonicotinoids were considered to be less toxic to aquatic organisms due to their low toxicity to standard test organisms Daphnia magna and Rainbow trout (Onchorhynchus mykiss), but recent studies have shown the opposite of this assumption. Partial aim of this study was, among summary of existing knowledges of the neonicotinoids in aquatic ecosystem and their impact on non-target organisms, also evidence toxicity of neonicotinoid preparation CALYPSO 480 SC, which contains 48 % of thiacloprid. Three species of crayfish were used to provide the toxicity Red swamp crayfish (Procambarus clarkii), Marbled crayfish (Procambarus fallax) and Yabby (Cherax destructor). To asses the toxiciy of Calypso, the acute toxicity tests on crayfish and acute immobilisation test on daphnia were used. The exposure time of tests were 96 and 48 hours. Juvenile crayfish were the most sensitive, their 96hLC50 ranged between 0.52 and 1.6 mg/l, 96hLC50 for older crayfish were between 1.94 and 27.3 mg/l. The 48hEC50 value for daphnia was 32.7 mg/l. During the acute toxicity test on crayfish, out of the mortality, changes in behavior of orgaisms were observed, the most frequent changes were the reduction of aggressiveness, slowing of motion of limbs, gills and breathing. Crayfish turned on their back, individuals were apathetic and died.
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