P24-31 Ecotoxicological Evaluation of the Insecticide Karate Zeon (Lambda-Cyhalothrin) on Non-Target Organisms: Dragonfly (Odonata) Larvae and Sinapis alba Seeds

The rapid growth of the human population has been accompanied by increasing and often excessive pesticide use. These compounds are known for their environmental persistence, remaining active for several decades. Through food chains, pesticides are biomagnified in the tissues of organisms. As the trophic level of individuals is higher, these hazardous substances increase and accumulate, threatening especially organisms at the top of the food pyramid. Although pesticides are primarily intended for controlling pest species, they also exert adverse effects on non-target organisms. The aim of this study was to evaluate the effects of the insecticide Karate Zeon, which contains the active substance lambda-cyhalothrin, on non-target organisms – specifically, dragonfly larvae of Anax imperator, dragonflies of the genus Libellula, and damselflies of the genus Coenagrion. Additionally, the insecticide was assessed using a seed germination and root growth inhibition test with white mustard (Sinapis alba). Testing on dragonfly larvae was conducted in one-liter aquaria, where the insecticide was applied at concentrations ranging from 0.05 to 50 ng of lambda-cyhalothrin per ml dechlorinated tap water. To assess acute toxicity, changes in larval behavior and mortality were monitored at 1, 5, 24, 48 hours, as well as 5 and 7 days. Incubation was carried out at 20±2 °C under a standard light/dark cycle. Mortality curves were plotted and toxicological index values calculated. The experiments showed that Karate Zeon is highly toxic to dragonfly larvae. The pesticide exhibits neurotoxic effects, with affected larvae displaying from severe convulsions and paralysis. The 48-hour LC 50 (lethal concentration for 50% of individuals) for lambda-cyhalothrin was determined to be 1.92 ng/ml. The Sinapis alba seed test was conducted in 150 mm Petri dishes. A series of test concentrations ranging from 3.125 to 50 ng of lambda-cyhalothrin per ml of dilution water was applied to the surface of filter paper placed in each dish, with a total volume of 5 ml per dish. Thirty white mustard seeds were then evenly distributed on the moistened paper. Incubation was conducted in the dark in a thermostat for 72±2 hours at 20±2 °C. The test parameter was the average root length of Sinapis alba seedlings after 72 hours, from which root growth inhibition was calculated. The 72-hour IC5 0 (inhibitory concentration for 50% root growth reduction) was determined to be 60.154 ng/ml. Based on the results of the acute toxicity tests on dragonfly larvae and white mustard seeds, it can be concluded that lambda-cyhalothrin – the active ingredient in the insecticidal product Karate Zeon – is toxic to these non-target organisms.