الفهرس 
The effect of some pathogenic fungi on tetranychus urticae koch and some associated predator mites in Egypt and Ethiopia
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Abstract
Entomopathogenic fungi and predatory mites can independently contribute to control the two-spotted spider mite Tetranychus urticae Koch. It is important to assess the risk of possible fungal infections in predators when a combination of them are being considered as a tandem control strategy for T. urticae in, Integrated Pest Management program (IPM). The first part of this study tested 4 Beauveria bassiana isolates and 2 Metarhizium anisopliae for virulence against T. urticae, egg and adult stages. Strains of B4 was found to be the most potent toward egg and adult stages, When it applied on the egg stage the hatchability was 25.2 % compared with the control which reached 99% and the LC50 was 1.14 x 107. Also it causes 88.5 % mortality for the adult stage at a concentration of 108spores/ml, and the LC50 was 6.57 x 106. The second part evaluated the pathogenicity of the most effective isolates which was B4, three concentrations were applied LC25, LC50 and LC90 against the adult of the two predator mites Phytoseiulus persimilis and Neoseiulus californicus.The bioassay results indicated that the B4 isolate was harmless against P. persimilis and slightly harmful against N. californicus. For more understanding, we used scanning electron microscopy (SEM), no viable fungal hyphae were found on predator cadavers. Observations with (SEM) revealed that conidia were attached to the cuticle of predatory mites within 24 h after spraying with B4strain, and had germinated within 24{u2013}48h. After 48h, conidia had gradually been shed from the mites, after none of the conidia penetrated the cuticular surfaces. In contrast, the germinated conidia successfully penetrate the cuticle of T. urticae, and within 72h the fungus colonized the mite{u2019}s body