Efficacy Bacillus thuringiensis var. israelensis serotype H-14 (Bti H-14) for control Aedes spp. density in Denpasar, Bali

Abstract

Background: A liquid bioinsecticide formulation containing Bacillus thuringiensis var. israelensis Serotype H-14 (Bti H-14) was tested in the field in household containers. The aim was to determine the effectiveness of Bti H-14 biolarvicide in controlling the density of Aedes spp. Larvae.Methods: This study was conducted in two phases of testing. First, to test the effective dose with 5 doses, namely (50 ul, 40 ul, 30 ul, 20 ul, and 10 ul) in 2.5 liters of water. Furthermore, the number of deaths was calculated after 24 hours of treatment and control by doing four repetitions. In the second phase, by conducting tests on containers in the household as many as 3171 containers were continuously observed every month, given Bti H-14 for 6 months. Observations were made before and after the application of Bti H-14 on larva density, mosquito density, and dengue cases. Data analysis was performed using paired t-test. Bti H-14 formulation to kill 50% of mosquito larvae (LC50) within 6 hours requires a concentration of 4 µl per liter.Results: Bti H-14 liquid formulation with delta-endotoxin and spores content of 600 ITU per ml or 1.2x109 CFU is effective in reducing larva density in household containers if done regularly.Conclusions: Bti H-14 liquid formulation is proven to be effective and easy to use for the control of Aedes larvae.