Diversity of indigenous entomopathogenic bacilli from domestics breeding sites of dengue hemorrhagic fever vector based on the toxicity against Aedes aegypti Larvae

Dengue Hemorrhagic Fever (DHF) is an endemic disease caused by Dengue Virus and transmitted by Ae. aegypti mosquitoes. The cities of Surabaya and Sidoarjo and Gresik have been the highest density of Ae. aegypti. The research aimed to show the diversity of indigenous entomopathogenic bacilli from domestics breeding sites of vector of DHF based on toxicity against Ae. aegypti larvae. The 30 soil samples from breeding sites of Ae. aegypti were taken from 10 sites in Surabaya and Sidoarjo and Gresik, respectively. Isolation of bacteria was performed using Bacillus sp. growth media, identified with Gram and spore staining, and toxicity test was performed on the third instar larval of Ae. aegypti. The result of toxicity test shown that the indigenous entomopathogenics Bacillus sp. was variative of divercity against Ae. aegypti larvae. The 133 isolates of Bacillus sp. was isolated, 45(33.8%) non toxic and 88(66.2%) toxic against Ae. aegypti larvae. From 88 isolates, 45(51%) isolates low toxic, 27(30.6%) isolates moderate toxic, and 16(18.1%) isolates high toxic against Ae. aegypti larvae. The 16 isolates of Bacillus sp. was high toxic to the third instar larvae of Ae. aegypti more than 50% mortality. The three highest potency of these Bacillus sp. were isolate code EG6.4 from Gresik and isolate codes ES7.3 and ES4.3 from Surabaya. Base on macroscopic, microscopic, and physiological characterizations the isolate code EG6.4 and ES7.3 were B. thuringiensis with similarity indexs 80.6%, and 78.12% respectively, and isolate code ES4.3 was Bacillus sphaericus with similarity index 71.4%.