Biological control of Tetranychus urticae Koch different stages on two cucumber cultivars (Sahm & Heikal) grown in
plastic houses in Nubaria District, Beheira Governorate, during 2004&2005 seasons was studied. Four predator
phytoseiid mites; Phytoseiulus macropilis (Banks), Neoseiulus californicus (McG.), N. cucumeris (Oudemans), and N.
zaheri (Yousef and El-Borolossy) were used against T. urticae different stages. N. californicus and P. macropilis gave
the highest reduction percentages of T. urticae different stages (97.36 & 97.51 % adults; 98.49 & 98.45% immatures
and 99.36& 98.59% eggs) in Sahm cultivar, while in Heikal cultivar the percentages were 87.14 & 92.50 %; 98.50 &
97.38 % and 97.87&97.85%, respectively during 2004. Similar results were obtained, during 2005. Chemical control by
spraying the two compounds Vertemic & Ortus proved that Vertemic was the best in reducing T. urticae different stages
by 89.55, 95.37 & 94.00% of the aforementioned successive prey stages. Integrated pest control, showed that releasing
N. californicus and P. macropilis after spraying Vertemic gave in general the high reduction of T. urticae different
stages but less than Vertemic alone. However using the two predators alone and not integrated with acaricides gave the
highest reduction percentages.