EFFECT OF BACTERIA BACILLUS THURINGIENSIS ON TWO SPOTS MITS TETRANYCHUS URTICAE UNDER LABORATORY CONDITION

This laboratory study was conducted at Al-Musayyib Technical College / Department of Biocontrol Technologies for the period from 1/9/2021 to 1/10/2021 in order to assess the efficiency of Bacillus thuringiensis in controlling the two-spotted mite Tetranychus urticae under laboratory conditions.The results showed that the bacterial suspension B. thuringiensis gave a significant effect on the roles of the two-spotted mite (larvae, nymphs and adults) at all concentrations, as it was observed that the mortality rate increased with increasing concentration and time period.While the bacterial sludge B. thuringiensis did not show any significant effect on egg mortality for all concentrations. It was observed that the concentration 33x 106CFU/ml increased the percentage of the destruction of motile stages of the two-spotted mite, which amounted to (63.33%, 53.33%, and 50.67%) for larvae, nymphs, and adults, respectively, for the time period (72) hours, which significantly differed from the control treatment, which amounted to (0.67%, 1.67%, and 1.33%) for larvae and nymphs.And adults, respectively, and for a period of time (72) hours. The lowest mortality rate for the moving roles of the concentration was 33x 10 2 CFU/ml (47.33%, 34.00%, and 32.00%) for larvae, nymphs, and adults, respectively, for the time period (72) hours, with a significant difference from the control treatment, which amounted to (0.67% and 1.67). % and 1.33% for larvae, nymphs and adults, respectively, for a period of time (72) hours.The study also showed an increase in the death rate with increasing the concentration of the bacterial sludge, where the highest concentration 33x 10 6 CFU/ml gave the highest mortality rate of (46.00, 41.56 and 41.44) for larvae, nymphs and adults, respectively, with a significant difference from the mortality rate for the lowest concentration 33x 10 2 CFU/ml, which reached (35.11, 23.44, and 26.22) for larvae, nymphs, and adults, respectively.It was observed that the mortality rate increased with the increase of the time period, where the period of 72 hours showed the highest mortality rate of (40.33, 34.17, and 31.08) for larvae, nymphs, and adults, respectively, with a significant difference from the lowest death rate for the 24-hour period, which amounted to (20.75, 16.92, and 19.58). ) for larvae, nymphs and adults, respectively.