Synergistic Action of Alpha-cypermethrin, Propolis Nanoemulsions and Other Activator Adjuvants for Peach Fruit Fly, Bactrcera zonata Management.

Abstract

The peach fruit fly, Bactrocera zonata (Saunders), is a major pest affecting over fifty tropical and subtropical fruit crops. It is a significant concern due to its rapid development of resistance to insecticides under intense selection pressure, alongside environmental and health concerns. This study investigated innovative nanotechnology-based adjuvants, specifically propolis nanoemulsions (PN), used alone or combined with selected activator adjuvants like tannin (T), argal (Si), and urea (U). The goal was to enhance the synergistic toxicological effects of alpha-cypermethrin (α-CP) and evaluate their impact on biochemical and biological parameters. Results demonstrated that the combination of α-CP with PN-Si-U achieved the highest control efficiency against adult B. zonata after 24, 48, and 72 h. Combinations of α-CP with PN-Si-U and α-CP with PN-T-U produced synergist ratios (SR) of 3.94 and 3.40, respectively (indicate the synergistic ratio of alpha-Cp alone). Further analysis revealed that α-CP (LC₂₅) and α-CP synergized with PN, PN-T, or PN-Si-U significantly altered levels of acetylcholine esterase, carbohydrate-hydrolyzing enzymes (trehalase, amylase), total protein, protease, and kinase enzymes in adult B. zonata through 24-h exposure versus untreated controls. Treatments with activator adjuvants also affected reproductive potential (fecundity, fertility/hatchability, sterility index), oviposition periods (pre-oviposition, oviposition, post-oviposition), adult performance (longevity, emergence), larval duration, egg incubation period, and pupal parameters (pupal period, pupation). These findings suggest that adjuvant-enhanced formulations will promote the efficiency of the insecticide doses used, delay resistance development, and mitigate environmental pollution.