Toxicity Studies of Bacillus thuringiensis on Non-Target Organism Daphnia sp. (Diplostraca: Daphniidae)
Sayyidatul Awalia Nuzula1, a) and Zulfaidah Penata Gama1, b)
1Department of Biology, Faculty of Mathematics and Natural Sciences, Brawijaya University, Malang, Indonesia.
Abstract
Dengue hemorrhagic fever is caused by dengue viruses that infect female mosquitoes, mainly of the species Aedes aegypti and to a lesser extent Aedes albopictus. One example of a bioinsecticide is Bacillus thuringiensis israelensis (Bti), which is a naturally occurring soil bacterium that can effectively kill mosquito larvae present in water. MOSNON™ is a biolarvicide product containing B. thuringiensis. The aims of this research were to analyze the effects of MOSNON™ toward mortality and behavior of the non-target organism Daphnia sp. This study was conducted at the Laboratory of Ecology and Animal Diversity and Laboratory of Microbiology, Faculty of Mathematics and Natural Sciences, Brawijaya University. The toxicity test used 10 neonates of Daphnia sp. for each bottle that contained 250 mL MOSNON™ solution. Toxicity test was divided into several concentrations of MOSNON™, they were 0, 5, 10, 15 and 20 ppm, and each experiment was repeated four times. Observations of Daphnia sp. mortality and behavior as well as abiotic factors (temperature, dissolved oxygen and pH) were conducted at exposure times of 0, 24, 48, 72 and 96 hours. Data were analyzed using ANOVA. The results showed that all concentrations of MOSNON had no effect on mortality or behavior of Daphnia sp. MOSNON™ is a potential biolarvicide for mosquitoes and safe for non-target organisms (Daphnia sp.).