Efficacy of five acaricides against the two-spotted spider mite Tetranychus urticae Koch and their side effects on some natural enemies

Five acaricides, Challenger, Ortus, Vertimec, Delmite and Bioca were investigated for controlling phytophagous mite, Tetranychus urticae Koch and their side effects on the predatory insects, mites and spiders at the El-Fayoum Governorate of cotton seedlings during the late season of 2007 and 2008. At the early seedling time, the application of the five tested compounds induced an average of 81.55%, 80.62%, 75.94%, 65.35% and 54.57% reduction in the population of spider mite during the 2007 season, and then changed to 79.72%, 77.92%, 72.54%, 60.05% and 47.97% reduction during the 2008 season. However, at the late season (fruiting time), the application of these compounds induced 83.24%, 84.11%, 76.34%, 56.29% and 59.57% reduction during the 2007 season changed to 84.78%, 84.94%, 77.31%, 55.58% and 58.68% reduction during 2008, respectively. As to the natural enemies, the highest reduction in the population after using the tested compounds was noticed for effect of Delmite during 2007 (33.79%), while the lowest ratio recorded when Ortus was used in the second season 2008 (18.53%). The side effect of the most important tested compounds (Challenger) was investigated in the laboratory against the predatory phytoseiid mite, Euseius scutalis.