Extraction of local isolates of Bacillus thuringiensis from vineyard soils in Salmas and evaluation of its toxicity on larva and adults of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Document Type : Research Paper

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Abstract

Bacillus thuringiensis is a gram-positive, spore-forming bacterium and terrcolous with abundant agricultural and scientific attractions throughout the world and are found in most climatic conditions. Due to genes Cyt, Cry and Vip proteins produced by this bacterium that infest and control specific agricultural pests including Lepidoptera, Coleoptera, Diptera, and even nematodes. For this purpose, 25 strains of indigenous Bt. bacteria separated from agricultural soils (Salmas city) and the amount of their toxicity were examined on the larvae and adult of T. castaneum. Bt. isolates based on morphological characteristics were isolated using acetate method. The morphological characteristics of Bt. crystal were studied by light microscopy. 25 isolates of Bt. was isolated and the most commonly isolates were pyramidal shapes. In the adult stage of this pest 40 percent of the isolates and in the larval stage eight percent of isolates were showed more than 25% and 75% losses respectively. General results showed that the bacteria have significant effect on larvae and adult of examined insects.

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