Controlling of the two-spotted spider mite, Tetranychus urticae Koch on three melon cultivars

Two predatory species (Phytoseiulus persimilis Athias-Henriot and Amblyseius swirskii Athias-Henrio), one biochemical compound Abamectin (Vapcomic) and one chemical compound (Ortus) as well as a control treatment were used to evaluate their effect in reducing the population densities of the two spotted spider mite, Tetranychus urticae Koch on three different melon cultivars (Shahd,Ananas and Galia) at Behaira Governorate during 2014 season. The average reduction percentage of spider mite, T. urticae population was significantly different among the different treatments on each of the Shahd (F _3,36 =15.65; P < 0.05), Ananas (F _3,36 =10.14; P < 0.05) and Galia (F _3,36 =13.75; P < 0.05; Table 2). The results of the overall mean reduction percentage of the spider mite populations on the three melon cultivars by the specialist predatory mite; P. persimilis was significantly highest (93.66%). Followed by the chemical compound Ortus and the biochemical control Vapcomic (79.07 and 75.94% respectively with no significant difference between them). While the generalist predatory mite, Amblyseius swirskii had the lowest significantly with the mean reduction percentage (56.93%). The results also implied that the shahd cultivar was relatively much tolerance to the spider mite, T. urticae infestation (38.85 individual/leaf; Table 1) than another tested cultivar (Ananas 82.72 or Galia 70.87 individual). Therefore, it could be concluded that cultivating the Shahd cultivar is preferable than Ananas or Galia cultivar and using P. persimilis for controlling T. urticae was superior than using the other methods.