Totally 25 actinomycetes were isolated by dry heat (70 oC) treatment method on Starch casein agar media, from the soil sample that was collected nearer to the root region of the mangrove Avicennia marina from the back water area, Ariyankuppam, Puducherry (UT). Mosquito larvae used in this study was Aedes aegypti. Among the 25 isolates, the isolate M20’s crude extract was found to better in controlling the larvae of Aedes aegypti mosquitoes. The active isolate M20 was identified as Streptomyces cacaoi sub sp cacaoi with 98.6% similarity with already reported sp. The isolate M20 was chitinase positive and it inhibits the growth and kills the mosquito larva effectively.