author(s)
Pathalam Ganesan, Sekar Anand, Subramanian Sivanandhan, Rajendran Host Antony David, Micheal Gabriel Paulraj, Naif Abdullah Al-Dhabi and Savarimuthu Ignacimuthu

abstract
The aim of the present study was to isolate Streptomyces enissocaesilis (S12-17) from the soil sample collected from Venganayakkan region in Western Ghats of Tamil Nadu, India and check for its mosquito larvicidal, ovicidal and repellent activities. Isolation was performed by serial dilution using spread plate technique. Extract from S. enissocaesilis was checked for mosqutiocidal activity by using standard methods. Ethyl acetate and methanol extract presented good larvicidal activity with LC₅₀ and LC₉₀ values of 207.18, 635.21 and 282.30, 894.13 respectively, at 500ppm concentration against Cx. quinquefasciatus. Ovicidal activity of ethylacetate crude extract was 100% and methanol extract was 89% at 500ppm concentration against Cx. quinquefasciatus. The ethyl acetate extract gave repellency of 127.2 min and the methanol extract gave repellency 80.6 min at 5mg/cm² concentration against Cx. quinquefasciatus. Both the extracts was harmless to tested non-target organism P. reticulata The active strain S12-17 was identified using 16S rRNA sequencing; phylogenetic tree was constructed using MEGA4 software; the sequence was submitted in the GenBank (Accession No. KT827105.1). The present study clearly showed that the extracts from S. enissocaesilis were effective in controlling mosquito life stages. The mosquitocidal activities deserved in this study, encourage the search of new insecticides having better properties.