Parasitology Research

, Volume 108, Issue 6, pp 1447–1455

Larvicidal, repellent, and ovicidal activity of marine actinobacteria extracts against Culex tritaeniorhynchus and Culex gelidus

Original Paper

DOI: 10.1007/s00436-010-2193-3

Cite this article as:
Karthik, L., Gaurav, K., Rao, K.V.B. et al. Parasitol Res (2011) 108: 1447. doi:10.1007/s00436-010-2193-3


The purpose of the present study was to assess the effect of crude extracts of marine actinobacteria on larvicidal, repellent, and ovicidal activities against Culex tritaeniorhynchus and Culex gelidus (Diptera: Culicidae). The early fourth instar larvae of C. tritaeniorhynchus and C. gelidus, reared in the laboratory, were used for larvicidal, ovicidal, and repellent assay with crude extracts of actinobacteria. Saccharomonospora spp. (LK-1), Streptomyces roseiscleroticus (LK-2), and Streptomyces gedanensis (LK-3) were identified as potential biocide producers. Based on the antimicrobial activity, three strains were chosen for larvicidal activity. The marine actinobacterial extracts showed moderate to high larvicidal effects after 24 h of exposure at 1,000 ppm and the highest larval mortality was found in extract of LK-3 (LC50 = 108.08 ppm and LC90 = 609.15 ppm) against the larvae of C. gelidus and (LC50 = 146.24 ppm and LC90 = 762.69 ppm) against the larvae of C. tritaeniorhynchus. Complete protections for 240 min were found in crude extract of LK-2 and LK-3 at 1,000 ppm, against mosquito bites of C. tritaeniorhynchus and C. gelidus, respectively. After 24-h treatment, mean percent hatchability of the ovicidal activity was observed. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. Crude extracts of LK-1 and LK-3 showed no hatchability at 1,000 ppm against C. tritaeniorhynchus and C. gelidus, respectively. This is an ideal ecofriendly approach for the control of Japanese encephalitis vectors, C. tritaeniorhynchus and C. gelidus.

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Environmental Biotechnology Division, School of Bio Sciences and TechnologyVIT UniversityVelloreIndia
  2. 2.Unit of Nanotechnology and Bioactive Natural Products, Post Graduate and Research Department of ZoologyC. Abdul Hakeem CollegeVelloreIndia