Evaluation of the Larvicidal Activity of Bacillus thuringiensis Compared with Chemical Insecticides Against the forth instar Larvae of the Culex Mosquito

Abstract

The aim of the study at the possibility of finding an integrated control program, consisting of the biological preparation made from the biocontrol (Bacillus thuringiensis) in combination with chemical pesticides (gentapride, metkol, methoprene) used to control Culex.

Each of the biological preparations made from Bacteria and chemical pesticides showed good efficiency in controlling, with a highly significant superiority to the chemical pesticide treatment, in which the death rate ranged between 100 and 88.66 %, compared to 73, 60, and 30% for the treatment of the biological preparation. And the chemical pesticide Metical had a death rate of 100% compared to (75, 66, 37%) for the treatment of the biological preparation. The chemical pesticide methane, in which the death rate ranged between (100, 90.66%), compared to (70.66, 55, 32%) for the treatment of the biological preparation.

The study also showed a compatibility between the biological preparation and the chemical pesticide by showing the bacteria Bacillus thuringiensis had a good ability to tolerate the chemical pesticide when they were both present in the culture medium (N.A), Nutrient agar, both individually at half and a quarter of the recommended dose. In addition to maintaining the mixture's efficiency in controlling Culex mosquitoes, the results showed superiority for the integration of the biological preparation, giving the highest death rate

The results of laboratory experiments showed that all concentrations of the treatments showed good efficacy in controlling the insect. They all affected the fourth larval stage of mosquitoes.