Efek Larvasida Bakteri Kitinolitik dari Limbah Kulit Udang terhadap Larva Aedes aegypti

Abstract

Aedes aegypti is a major vector for Dengue, a deadly disease causing death of millions of people in developing countries both in urban and rural populations. Ae. aegypti control using chemical insecticide was always carried out and lead to a widespread insecticide resistance. Therefore, mosquito biological control is needed to replace the usage of chemical insecticide. A chitinolytic bacteria, was isolated from shrimp’s waste (head and shell). The isolate showed chitinolytic activity as a transparent zone in colony inside the synthetic media, containing (w/v)- 0,3 % colloidal chitin, 1% pepton, 0,5% yeast extract, 0,1% NaCl, 0,1% K₂HPO₄, 0,05% MgSO₄.7H₂O, 0,001% FeSO₄.7H₂O, 0,001% ZnSO₄.7H₂O, and each of 0,0001% CuSO₄.5H₂O, MnSO₄.nH₂O and CaCl₂.2H₂O at pH 7 and  30⁰C after 72 h of incubation. The isolate was identified as gram positive group based on gram staining. In the experimental method, four concentrations of chitinolytic bacteria (4%, 8%, 16% and 32%) was exposed to Ae. aegypti larvae. The result showed that chitinolytic bacterium degrades exoskeleton of third instar larvae of Ae. aegypti. Degradation of exoskeleton started on the 2^nd days and occurred in thorax region. Probit analysis showed LC₅₀ value was obtaninedat concentration of 2%.