Title:Természetes piretrin toxicitásának elemzése ragadozó Copepodákra és pontyfélék ivadékállományaira
SUMMARY The production results of pond fish culture highly depends on the success of fry rearing process. The plankton selection is an important agricultural intervention when different synthetic insecticides are used for the elimination of the predatory Copepods species for example: Cyclops ssp. The purpose of our investigation was to develop a new plankton selection method which is environmental friendly and can substitute the synthetic insecticides. We investigated the Bioplantella Flora product which is a natural plant-origin preparation. The agent of this product is natural piretrin. The laboratory tests show that it can kill 86% of Copepods in 1 ppm concentration during 48 hours and the 0.5 ppm concentration can decrease the feeding activity of predatory Copepods. As a result of fish tests, 30% toxicity concentration was measured in solution of 1 ppm after 24 hours. There was no statistical effect of natural piretrin on larvae in lower concentration (≤ 0.5 ppm) and experiment of fish changing showed that the drug is rapidly degraded.