Larvicidal Effect of Mixture of Beauveria bassiana Crude Metabolite and Chitinase Enzyme against Aedes aegypti Larvae

Abstract

Aedes aegypti is a major vector of dengue, a deadly disease causing deaths of millions of people in developing countries. Aedes aegypti control with chemical insecticide is widely used, and affects on a widespread insecticide resistance. Mosquito biological control was needed to replace the use of chemical insecticide. This study aimed to evaluate larvicidal effect of mixture of Beauveria bassiana crude metabolite and chitinase enzyme against Aedes aegypti larvae. An experimental study using completely randomized design was conducted in March-April 2016 at Banjarnegara Research and Development Unit for Zoonosis Control. Biolarvacide formula was made of mixture with 2 : 1 ratio between Beauveria bassiana crude metabolite and chitinase isolated from chitinolytic bacteria, which was propagated by the Agency's Bacteriology Laboratory. In experimental method, 120 Aedes aegypti larvae (the third instar) were exposed with four concentrations of biolarvacide formula (4%, 8%, 16%, and 32%) in 3 replicates. Results showed that exposure of biolarvacide formula caused the third instar larval mortality which started on the first day of exposure. Probit analysis showed LC 50 value was obtained at concentration of 53.2 ppm. This shows that larvacide formula of Beauveria bassiana and chitinase enzyme compounds are effective to be used as larvacides against Aedes aegypti larvae. Keywords: Aedes aegypti, Beauveria bassiana, larvacide AbstrakAedes aegypti merupakan vektor utama demam berdarah dengue (DBD) penyakit mematikan yang menyebabkan kematian jutaan orang di negara berkembang. Pengendalian Aedes aegypti dengan insektisida kimia banyak digunakan dan menimbulkan dampak resistensi insektisida yang meluas. Pengendalian nyamuk secara hayati diperlukan untuk menggantikan penggunaan insektisida kimia. Penelitian ini bertujuan untuk mengetahui efek larvasida campuran metabolit sekunder Beauveria bassiana dan enzim kitinase terhadap larva Aedes aegypti. Sebuah penelitian eksperimental dengan desain rancangan acak lengkap dilaksanakan pada bulan Maret-April 2016 di Balai Litbang P2B2 Banjarnegara. Formula larvasida hayati dibuat dari campuran dengan perbandingan 2:1 antara metabolit sekunder jamur Beauveria bassiana dan enzim kitinase yang diisolasi dari bakteri kitinolitik biakan Instalasi Bakteriologi Balai Litbang P2B2 Banjarnegara. Dalam metode eksperimen, sebanyak 120 ekor larva Aedes aegyppti (instar III) dipaparkan dengan empat konsentrasi formula larvasida hayati (4%, 8%, 16% dan 32%) dengan tiga buah ulangan. Hasil penelitian menunjukkan bahwa formula larvasida hayati menyebabkan kematian larva instar III Aedes aegypti yang dimulai pada hari pertama paparan. Hasil analisis probit menunjukkan nilai LC 50 campuran Beauveria bassiana dan enzim kitinase sebesar 53,2 ppm. Hal ini menunjukkan bahwa formula larvasida dari campuran Beauveria bassiana dan enzim kitinase efektif untuk digunakan sebagai larvasida terhadap jentik Aedes aegypti.

Control methods for invasive mosquitoes of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Indonesia

“…In addition, B. bassiana has proven effective against Ae. albopictus in the third instar larvae, where a larvicidal formula of the enzyme compound B. bassiana and chitinase was effectively used as a larvicide [ 54 ]. This novel approach could serve as a promising basis for practical and economical strategies to reduce viable Aedes mosquito egg populations.…”