Ethology of Sunn-pest oviposition in interaction with deltamethrin loaded on mesoporous silica nanoparticles as a nanopesticide

Background: Wheat is one of the main food for around 2 billion people worldwide. Among the biological stressors, Eurygaster integriceps Puton is a damaging insect in wheat and barley fields, which harms them both quantitatively (by overwintered adults) and qualitatively (by instar nymphs). The ovipositional and the new generation's production control are pivotal approaches to control the severe damages of Sunn-pest. Methods: In this study, to enhance the deltamethrin effectiveness while reducing its required dosage and also reducing the adverse health and environmental impacts, a novel MSN-based deltamethrin formulation was prepared and evaluated based on the laying-eggs number and oviposition behavior. To this, deltamethrin was loaded on KIT-6 mesoporous silica nanoparticles and characterized using SEM, TEM, and TGA analysis, and the insect potential of deltametrin@KIT6 was then evaluated. Results: The results showed that there might be differences between the treatments (KIT-6, deltamethrin@KIT-6, deltamethrin commercial formulation, and water as a control) in terms of the insect control via the laying-egg and next-generation prevention. The results showed that KIT-6 and deltamethrin@KIT-6 could reduce the oviposition rate compared to water as the control. Deltamethrin@KIT-6 not only caused the less oviposition done but the eggs were scattered and the batch of eggs did not have a uniform-shape similar to the control mode. The deltamethrin@KIT-6 nanopesticide could increase the pesticide effectiveness by reducing the Sunn-pest's oviposition and nymphal population and subsequently decreasing the damage caused by them. So that the concentrations of 10, 25, and 125 mg L-1 of deltamethrin@KIT-6 reduced oviposition by 63.24%, 66.11%, and 67.62%, respectively, compared to the control group. On the other hand, descriptive observations showed that another possible tension is created through insect eggs deposition on the boundary layer of leaves. Conclusion: The MSN-based nanoformulation could be effectively considered to control the next-generation population density of Sunn-pest.

Automated summary

The MSN-based deltamethrin@KIT-6 nanoformulation can effectively control the next-generation population density of Sunn-pest, reducing the damage caused to wheat and barley crops.