Antagonistic potential of Steinernema kraussei and Heterorhabditis bacteriophora against Dengue fever mosquito Aedes aegypti

Abstract

The present investigation was undertaken to control A. aegypti procured from three different breeding sites i.e., canal water, tap water and sewage water by utilizing the antagonistic potential of two entomopathogenic nematodes Steinernema kraussie and Heterorhabditis bacteriophora. The trial was conducted in Vector Ecology Lab, Department of Entomology and Plant Nematology Lab, Department of Plant Pathology, University of Agriculture, Faisalabad, Pakistan during Feb-April, 2016. The mortality rate of A. aegypti larval population was assessed at two different concentrations 70 and 100 infective juveniles (IJs) of both EPNs at variable temperature of 20, 30 and 40 oC for 24, 48, 72 and 94 hrs time intervals. S. kraussei and H. bacteriophora produced best mortality at 20 oC and 30 oC being the optimum temperatures for their activity respectively. S. kraussei at the concentration of 100 IJs produced 100% mortality of A. aegypti bred in canal, tap and sewage water at 20 oC after 48 and 96 hrs. H. bacteriophora at the concentration of 100 IJs produced 100% mortality of A. aegypti from all breeding sites at 30 oC after 96 hrs. Activity of S. kraussei was significantly decreased with rise in temperature up to 40 oC, whereas; activity of H. bacteriophora was less at low temperature and increased significantly at higher temperature. Increased concentration of IJs and higher time intervals were also found to be directly proportional with mortality rate.