BIOSAFETY OF POLYMER-BASED AZADIRACHTIN SILICA NANO-FORMULATION TO TRICHOGRAMMA PRETIOSUM AND CHRYSOPERLA ZASTROWI SILLEMI

Abstract

IPM strategies require sustainable alternatives to conventional chemical pesticides to minimise non-target risks while delivering similar efficacy. While botanical insecticides present a promising alternative, their field utility is limited by photodegradation and low persistence. To address this, an Azadirachtin-Silica-Chitosan nano formulation was developed using mesoporous silica nanoparticles (MSNs) and characterised to assess particle size and stability. Before field adoption, we should evaluate the ecotoxicological impact of this nano-formulated biopesticide on beneficial arthropods. This study evaluated the impacts of the Azadirachtin–Silica–Chitosan nano-formulation on two key biocontrol agents: Trichogramma pretiosum and Chrysoperla zastrowi sillemi. Based on previous laboratory experiments conducted for thrips, this study utilized single and double concentrations of LC50 and LC90 (100, 200, 1250 and 2500 ppm). Bioassays assessed exposure effects on mortality and development compared with commercial Neemazal T/S (3 mL/L) and the insecticide cyantraniliprole 10.26 OD (1.8 mL/L). Results showed that at lower concentrations of 100 and 200 ppm, the nano-formulation was essentially harmless to the development of both biocontrol agents; however, at higher concentrations of 1250 and 2500 ppm, low to moderate toxicity was observed, highlighting the need for concentration management to protect non-target organisms. The higher doses have limited practical applicability, proving the safety of the nano-formulation towards non-target organisms at a field-applicable rate.