SiO₂ applications as an alternative to insect control in greenhouses

Silicon dioxide (SiO₂) has been extensively studied as an alternative method to pest management chemical applications in agriculture. The present work aimed to evaluate the insecticidal efficacy of different SiO₂ dust formulations and their effectiveness when integrated into the textiles of an insect-proof net. For this reason, Sitophilus oryzae and Tribolium confusum were exposed to three inert dust formulations, namely Sylobloc® S200, S200-OH, and S200MEC to investigate their effect on the mortality of the aforementioned stored-product insects. The results of this series of bioassays showed that Sylobloc® S200 was the most effective dust among all the formulations tested. Thus, five samples of the same 50 mesh size insect-proof net were coated with the S200 dust followed either by different coating repetitions or by the addition of paraffin. T. confusum was indicated as the most tolerant species, as the recorded mortality rate was significantly low when exposed to all samples tested. However, the mortality rate of S. oryzae was strongly related to the coating repetition as well as the exposure intervals. The highest mortality (70%) was detected after 7 days of exposure to the net and it consisted of three coating repetitions while no paraffin was added to its surface. The results of the present study underline the insecticidal efficacy of SiO₂ treated nets against storage insects and their subsequent application in greenhouses for the control of more susceptible insects. This research has been co-financed by the European Union and Greek national funds through the National Action “Bilateral and Multilateral E&T Cooperation Greece-Germany”(project code: T2DGΕ-0120).