The Grey Scales Insects was considered as one of the pests which impact the all date palm varieties and the date itself, To avoid using of chemical pesticides and its negative impacts on the whole agroecosystem,Two isolates of the entomopathogenic fungi Lencanicillium (Verticillium) lecanii (Zimm) Zare and Oami were also used against the forementioned immature and mature stages of P.blanchardi under both laboratory and field conditions. The Results showed the different in the killing percentageof insect eggs, according to the tested concentrations as well as the period that followed the transaction, which saw the focus (1 × 108)spore / ml in record proportions killings amounted to the isolation of imported fungi 93.4% after 14 days of treatment in isolation amounted to 90.7% of local fungi.
The results also showed rapid growth and evolution of fungal isolates the nymphs crawling starting from 3 day of treatment, and that the short time during which he managed to kill nymphs compared to their impact on insect eggs. The impact on nymphs variation by age, where it has made a focus (1×106)spore /ml ratios were killed amounted to 99.2 and 97.4 of imported and local fungi respectively on crawlers ,sessile nymphs 93.2 and 94.2% respectively in the same concentration, while the killing percentageto the adult in the same time period and concentration 97.4, 95.2% respectively.The adoption of the highest concentration of each isolation (1 × 108)spore/ ml, which have been tested against the insect fields, in the role of the egg isolates did not give any ratio was killed after 3days of treatment to local and imported isolation, while reached 89.9, 79.8%, respectively, after 21days of the treatment and while imported excelled on the local isolation against the role of the nymph crawlers and reached the highest killing percentage of the two 89 and 73%, respectively, after 21 days of treatment, in the sessile nymphs it did not record any killing percentage after 3 to 7 days of treatment, but they gave the highest effectiveness after 21days as the percentage of local and imported 90.2 , 88% respectively. The adult was affected by limited rates in the first periods of treatment, but they gave the highest killing percentage after 21days 93.9, 87.6% respectively. |