Seasonal population development of Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) was studied on three different bean cultivars in five bean field (Central, Edremit and Gevas provinces) of Van, during 2006-2007. The studies were carried out on Phaseolus vulgaris L. (green bean, white bean and gina F(1) varieties) in Gevas, on P. vulgaris (green bean) in Edremit and Van/Central provices. The population development of T. urticae started in July and reached a maximum in late September and early October. In these periods, the beginning to dry of plants was observed due to the high population levels of T. urticae. On the other hand, predator insects Scolothrips longicornis Priesner, 1926 (Thysanoptera: Scolothripidae), Stethorus punctillum Weise, 1891 (Coloeptera: Coccinellidae) and Orius sp. (Hemiptera: Anthocoridae) were determined as the most abundant predator species in the bean fields. Especially, S. longicornis and Orius sp. were determined to be effective on the population development of T. urticae in the period of the increase of red spider mite. The predator insect S. punctillum was determined only in Center research area which it's around was bordered with apple orchards.