Abstract
Silver Nanoparticles (AgNP) have become one of the most promising approaches for pest control in recent years. The present study aimed to evaluate the effects of silver nanoparticles on all stages of eriophyid mite, the tomato russet mite, Aculops lycopersici (Massee) (Acari: Eriophyidae) and tetranychid mite, the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). This includes its impacts on phytoseiid predators, Euseius scutalis (Athias-Henriot) and Neosiulus cucumeris Oudemans (Acari: Phytoseiidae), on tomato plants under greenhouse conditions. Four different concentrations of silver nanoparticles (53.94, 107.88, 161.82 and 215.76ppm) as well as the control (well water) were examined. The obtained results indicated that the mortality percentage of both phytophagous and predatory mites were associated with an increase of the concentrations of silver nanoparticles. Silver nanoparticles were found to be significantly effective in killing A. lycopersici and T. urticae with minimal effects on E. scutalis and N. cucumeris. The mortality percentage was 20.88, 45.34, 72.80 and 93.37% for A. lycopersici and 18.99, 42.69, 73.21 and 85.21% for T. urticae while the mortality percentage was 2.39, 8.66, 17.48 and 23.77% for E. scutalis and 4.43, 12.71, 14.42 and 19.95% for N. cucumeris one week after exposure to 53.94, 107.88, 161.82 and 215.76ppm of silver nanoparticles, respectively. Moreover, the findings showed that silver nanoparticles caused a reduction in the percentage of eggs hatching. The percentages of larvae hatching from eggs were 68.11, 49.73, 34.55 and 20.36% for A. lycopersici and 79.20, 64.36, 43.30 and 30.29% for T. urticae one week after exposure to silver nanoparticles at 53.94, 107.88, 161.82 and 215.76ppm, respectively, compared with the control (well water). This research proved that the implementation of silver nanoparticles at low dosages could reduce the population of phytophagous mites associated with tomato plants, with low detrimental effects on non-target mites.