Haq_2025_Insects_16_

The tomato leafminer (Tuta absoluta) is a globally invasive pest that causes severe yield losses in tomato crops. Nanotechnology-based strategies offer promising alternatives to conventional insecticides. This study examines the physiological, biochemical, and demographic responses of T. absoluta following exposure to mesoporous silica nanoparticles (MSNs) applied to tomato leaves at concentrations of 0, 3, 30, and 300 mg L(-1). Comprehensive assessments were conducted, including digestive and detoxifying enzyme activities in the insect, neurotoxicity indicators, life table parameters, and antioxidant responses in the host plant. At 30 mg L(-1), MSNs significantly impaired larval development, fecundity, and survival of T. absoluta without inducing phytotoxicity. Tomato plants treated at this concentration exhibited enhanced antioxidant enzyme activity (SOD, CAT, POD) and a reduced malondialdehyde (MDA) content, indicating an active oxidative defense. These plant responses were significantly correlated with changes in insect fitness traits, suggesting a plant-mediated effect on pest physiology. Digestive enzyme disruption, decreased acetylcholinesterase activity, and extended developmental periods contributed to suppressed population growth, as evidenced by reductions in the intrinsic rate of increase (r), net reproductive rate (R(0)), and fecundity. At 300 mg L(-1), however, severe phytotoxicity and enzymatic collapse were observed in both plant and insect systems. These findings highlight moderate concentration of MSNs (30 mg L(-1)) as a promising dose for sustainable and host-safe pest management, offering multi-targeted suppression of T. absoluta through combined plant and insect biochemical pathways.