Enhanced Insecticidal Activity of Orizon and Oxymatrine by Silica Oxide Nanoparticles to control Tuta absoluta (Lepidoptera: Gelechiidae)

The tomato Leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae), is one of the extreme agricultural pests. Nanoparticles have been developed as an alternative tool for pest management currently. In this study commercially silicon oxide nanoparticle (SiO-NPs) was used alone or with a Orizon or Oxymatrine nanocomposite were synthesized and we conducted laboratory and greenhouse experiments to evaluate their effect on 4th instar larvae of Tuta absoluta on tomato, Solanum lycopersicum L. In the laboratory experiment, three bioassay experiments with 4th instar larvae of Tuta absoluta. Firstly, applying SiO-NP at 25, 50 and 75 ppm caused 34, 38 and 49% mortality, respectively. Secondly, using SiO-NPs at 25, 50 and 75 ppm with Orizon at the recommended concentration nanocomposite caused 46, 55 and 66% mortality, respectively. Thirdly, using SiO-NPs at 25, 50 and 75 ppm with Oxymatrine at the recommended concentration nanocomposite caused 46, 55 and 66% mortality, respectively at 72 h after treatment. while the Orizon and Oxymatrine treatments gave larval mortalities of 34 and 36%, respectively. In the greenhouse experiment, the SiO- Oxymatrine treatment recorded the lowest numerical density of 4th instar larvae, which was 0.91 larva/leaf, and the average larval density decreased as a result of the treatments SiO –Orizon, Oxymatrine, Orizon and SiO NPs to 0.96, 1.07, 1.15 and 1.25 larva/leaf, respectively, compared to the control treatment reached 4.31 larva/leaf at 14 day post-treatment. the results also showed highest density was recorded on the Omnia reaching 2.31 larva/leaf, while recorded Oula, Jeda and Kantor hybrids recorded less numerical density were 1.93, 1.52 and 0.79 larva/leaf, respectively These results suggest that the application of SiO- Oxymatrine and SiO –Orizon at 5 ppm can be used as an eco-friendly controlling strategy of T. absoluta.