Field trials of Bacillus thuringiensis subsp. israelensis De Barjac formulation (Vectobac 12 AS) for control of culex (Culex) tritaeniorhynchus giles (Diptera: Culicidae) in Belek, Turkey

Abstract

In this study, the efficiency and residual activity of aqueous suspension of Bti formulation, Vectobac* 12 AS which has a potency of 1200 International Toxicity Units per mg (1200 ITUs/mg), was evaluated for control of Culex {Culex) tritaeniorhynchus Giles (Diptera: Culicidae). Field trials were conducted in eight small sized plots in Belek. 250 ml/ha, 500 ml/ha, 750 ml/ha and 1000 ml/ha dosages were used in pasture breeding habitat with high vegetation cover. In addition to the former trials, 500 ml/ha and 1000 ml/ha dosages were tested in marshy breeding habitat with semi vegetation cover. Mean larval density of pretreatment and posttreatment were compared and the 24-h posttreatment efficiency and residual activity of Vectobac® 12 AS were evaluated. The 81.16% reduction in total mean larval densities obtained at 24-h posttreatment with 500 1/ha dosage of Vectobac® 12 AS in marshy habitat started to drop consistently after the 2nd day and it was found to be 37.80% at the 6th day.